According to your recounted history with the bike, it was running fine before the alterations.
Logic says something either isn't right about the electronic ignition install, or something got changed while that was going on.
It is totally possible this is a brand new fault that popped up, but normally IT"S THE LAST THING WORKED ON.
I swear, troubleshooting should be tought in grade school! It's one of those life skills needed for just about everything in life. This is one of the simplest of the troubleshooting maxims - and no one's pointed it out yet!
Of course I can understand getting flustered when things go wrong and having little or no understanding of the equipment worked on. That's a problem right there!
Another one of the troubleshooting maxims that goes hand in hand with the work thus far: - MAKE ONLY ONE CHANGE AT A TIME.
It would have made pinpointing the fault that much easier had the bike been test ridden after each change. Now you don't know which of the changes caused it and will need to check them all out.
Wanted: Dead, smashed, crashed or trashed gauges
BMW GAUGE REPAIRS - TACH*SPEEDO*CLOCK*VOLT METER *PODs & LIGHT BOARD*