Dear Dane,
I hope mr.Dowson finds anything in your FSUIPC ini and the most recent log you sent, that might eventually point to the cause of the applause you're hearing.
For the time being, start your flight and keep the main UI of VoiceMeeter open. Keep an eye at the local section of apps for audio activity - I hope that you have your main virtual B1 local input bus mapped to your hardware A1 with your Realtek integrated sound card tied to it and set as the default audio device ?
That is used by the simulator, so make sure the applause you are hearing is coming from the B1 - and also that you hear it from the A1 !
Because you have a few more devices there, and I see you also route 3 virtual audio cables - you also maybe use VBAN for interfacing any sound devices or streams within your LAN.
Anyway, take a good look at all those sources, start the VB monitor for each of those buses and find out where the applause is coming from - you can identify the source executable if it is coming from any of the local virtual sources, it will appear on the main VoiceMeeter UI.
But...if you use ASIO on A1, then all of this is done differently - although if you are familiar with the ASIO routing and you have your audio system set up trough it, you surely know what you're doing and have every single bus/line/channel clearly in your mind.
The point is that you have a full small home audio routing system with mixing in place of the default Windows OS audio system - you should search for the source of that applause trough it.