The PTFE guide issues rears its ugly head every so often on the forum. @Olias has a very detailed post about his struggles.
I’ve seen users that print covers for the Z bearing well in the floor. The problem is that newer machines have longer bearings and so when their bed drops all the way to the bottom, the z bearings are pushed up and cause homing issues.
Users have printed covers for the steppers and this causes the printer to loose steps every time they print in the back corner or purge filament.
Pretty much what it boils down to, if your having homing, position or filament loading problems, remove all “mods” and see if that fixes the problem. It does for a good number of people on the forum. Hence my warning.