The most useful thing I learned was my first security hack. Floppies (all we had) could be password-protected. The teacher's disks (with the video games) were password-protected so we couldn't copy or alter them. So put in your disk. Enter "current password". Replace it with teacher's disk. Enter "new password"...
Limiting the scope of what you're seeing is no longer a luxury, it has become a necessity to get any work done but this tendency to want to understand everything is hard to get rid of and a huge time-sink.
Couple that with the speed with which formats, protocols and technologies are obsoleted and you end up with an even more frustrating situation.
I suspect the next level of major real progress will come from simplification or a total reboot.
Even amongst actual TRS-80's, the Model I is only partly compatible with the Model III and Model 4.