Kevin -
I've captured the telnet output from several paths through *93/#93 menu mode. I have not removed anything from within each excerpt. While  the webapp display was frozen, I continued answering prompts using the webapp keypad while watching the telnet output. 
During this "frozen" time only every 2nd to 4th webapp keypress is sent (seen?) by the AD2USB!- Code: Select all
 [000100010000--------],0da,[f707000000da800c08020000000000],"P1   DISARMED   Hit * for faults"
!Sending.done
[100100010000--------],000,[f70800000000801c08020000000000],"GUEST HOUSE       READY TO ARM  "
!Sending.done
[000100010000--------],100,[f70000000000800c080200000d0000],"SYSTEM  12      STATUS  NR      "
!Sending.done
!Sending.done
[000110010000--------],0ed,[f73f000000ed000048020000000000],"  Program Mode  Please Stand By "
[000110010000--------],000,[f70400000000800048020000000000],"Program Mode    * Fill # View-00"
!Sending.done
[000110010000--------],000,[f70400000000800c48020000000000],"Enter Fill Field             -  "
!Sending.done
[000110010000--------],090,[f70400000090800448020000000000],"Enter Fill Field             -9 "
!Sending.done
******** Now the webapp display freezes, continuing to show the above message.
[000110010000--------],193,[f70400000093800048011f000d0000],"ZONE PROG. ?     1=YES  0=NO   0"
!Sending.done
[000110010000--------],093,[f70400000093800048011f00000000],"EXPERT MODE ?    1=YES  0=NO   0"
!Sending.done
[000110010000--------],093,[f70400000093800048011f00000000],"ALPHA PROG. ?    1=YES  0=NO   0"
!Sending.done
[000110010000--------],093,[f70400000093800048011f00000000],"DEVICE PROG. ?   1=YES  0=NO   0"
!Sending.done
[000110010000--------],093,[f70400000093800048011f00000000],"RELAY PGM ?      1=YES  0=NO   0"
!Sending.done
[000110010000--------],193,[f70400000093800048011f000d0000],"RLY VOICE DESCR  1=YES  0=NO   0"
!Sending.done
[000110010000--------],093,[f70400000093800048011f00000000],"CUSTOM INDEX     1=YES  0=NO   0"
!Sending.done
[000110010000--------],193,[f70400000093800048011f000d0000],"QUIT MENU MODE?  1=YES  0=NO   0"
!Sending.done
[000110010000--------],000,[f70400000000800048021f00000000],"Program Mode    * Fill # View-00"
******** At this point the webapp display resumes, displaying the above message.
Here's an alternate path, where instead of exiting menu mode I answer yes to enter zone programming. After freezing at the same point, the only subsequent message displayed is the zone summary.
- Code: Select all
 [000110010000--------],0ed,[f73f000000ed000048020000000000],"  Program Mode  Please Stand By "
[000110010000--------],100,[f704000000008000480200000d0000],"Program Mode    * Fill # View-00"
!Sending.done
[000110010000--------],000,[f70400000000800c48020000000000],"Enter View Field             -  "
!Sending.done
[000110010000--------],090,[f70400000090800448020000000000],"Enter View Field             -9 "
!Sending.done
******** At this point the webapp display is frozen.
[000110010000--------],193,[f70400000093800048011f000d0000],"ZONE PROG. ?     1=YES  0=NO   0"
!Sending.done
[000110010000--------],093,[f70400000093800048011f00000000],"Set to Confirm?  1=YES  0=NO   0"
!Sending.done
[000110010000--------],193,[f70400000093800048011e000d0000],"Enter Zone No.  00=QUIT       01"
!Sending.done
!Sending.done
[000110010000--------],093,[f70400000093800048011f00000000],"Enter Zone No.  00=QUIT       0 "
[000110010000--------],093,[f70400000093800048011e00000000],"Enter Zone No.  00=QUIT       03"
!Sending.done
[000110010000--------],193,[f70400000093800048021e000d0000],"03  ZT P RC INL     01 1 03 HW1 "
******** At this point the webapp display resumes, displaying the above message.
******** I enter "#" to back out to the zone entry prompt.
******** The webapp display is once again frozen on the above message.
!Sending.done
[000110010000--------],093,[f70400000093800048011e00000000],"Enter Zone No.  00=QUIT       04"
!Sending.done
!Sending.done
[000110010000--------],193,[f70400000093800048011f000d0000],"Enter Zone No.  00=QUIT       0 "
[000110010000--------],093,[f70400000093800048011e00000000],"Enter Zone No.  00=QUIT       00"
!Sending.done
[000110010000--------],093,[f70400000093800048011f00000000],"QUIT MENU MODE?  1=YES  0=NO   0"
!Sending.done
[000110010000--------],100,[f70400000000800048021f000d0000],"Program Mode    * Fill # View-00"
******** At this point the webapp display resumes, displaying the above message.
Finally, here's an excerpt where instead of backing out after the zone summary I enter "*" repeatedly to step through the zone programming prompts, accepting each of the current values. This excerpt begins with the display frozen on the  "Enter View Field             -9 " message...
- Code: Select all
 [000110010000--------],093,[f70400000093800048011e00000000],"Enter Zone No.  00=QUIT       03"
!Sending.done
[000110010000--------],193,[f70400000093800048021e000d0000],"03  ZT P RC INL     01 1 03 HW1 "
******** At this point the webapp display resumes, displaying the above message.
******** I enter "*" to move forward to the next entry prompt.
******** The webapp display is once again frozen on the above message.
!Sending.done
[000110010000--------],193,[f70400000093800048011e000d0000],"03 Zone Type    ENTRY/EXIT 1  01"
!RFX:0043917,04
!RFX:0043917,04
!RFX:1004740,04
!RFX:0836928,80
!RFX:0836928,00
!RFX:0836928,80
!RFX:0043917,04
!RFX:0836928,00
!RFX:0043917,04
!RFX:0811886,34
!RFX:0811886,34
!RFX:0482614,80
!RFX:0482614,00
!RFX:0639091,04
!RFX:0164010,24
!RFX:0639091,04
!RFX:0043917,04
!RFX:0043917,04
!Sending.done
[000110010000--------],093,[f70400000093800048011f00000000],"03 Partition                   1"
!RFX:1038728,a0
!RFX:1038728,a0
!Sending.done
[000110010000--------],193,[f704000000938000480114000d0000],"03 Report Code  1st 00 2nd 03 03"
!Sending.done
[000110010000--------],093,[f70400000093800048011b00000000],"03 Report Code  1st 00 2nd 03 0 "
!Sending.done
[000110010000--------],193,[f70400000093800048021b000d0000],"03 Report Code  1st 00 2nd 03 03"
!RFX:1038728,80
!RFX:0523192,24
!RFX:0523192,24
******** The display resumes (unsure if before or after the !RFX msgs)
******** with the above message. I enter "*" to move forward to the next
******** entry prompt. The webapp display once again freezes,
******** continuing to show the above message.
!Sending.done
[000110010000--------],193,[f70400000093800048011e000d0000],"03 Input Type   Hardwire      01"
!RFX:0514398,24
!RFX:0514398,24
!Sending.done
[000110010000--------],093,[f70400000093800048021e00000000],"03  ZT P RC INL     01 1 03 HW1 "
******** Again the display resumes, but is stuck
******** on the above message until out of menu mode.
Hopefully this gives you enough to go on. I thought about adding screenshots, but since the messages are in the telnet stream verbatim decided there was no value add. Also, just to be thorough, let me state that I have no filtration of panel messages set up.
Please let me know if you need me to conduct further tests...
Thanks,
Peter