I'm not new to bikes ive built countless gsxr s and r1/r6 with no problems if there is a odd problem i search then ask i dont want jokes or bs if i did id search jokes im asking for technical advice cause I haven't found the the obvious problems IE stator or voltage regulator or battery ....
Which is why you have been asked if you have a meter, and the manual.
The charging system is pretty simple; you have already replaced almost all the parts involved. Your mechanics may have some idea of what they are telling you -- the fixed magnets in the charging system could have been damaged in a fall. A sharp shock when they are hot will cause them to become weaker.
But you can only tell that, if you have a meter and make the measurement. Output from the alternator with the bike running is going to be in AC Volts. the points you need to make the reading at are identified in that shop manual. That gives you clear guidance on pass/fail.
You will eventually have to develop a table of what has been done and what remains to do.
If the parts you changed did not result in proper performance, then something you missed must be the cause, right? But we don't know without numbers.
This can be identified with Voltage readings, or resistance readings. Unlikely to find the issue with your eyes. -- you might get lucky and find a melted wire, or one that is burnt through.
Typically with these kinds of problems the first thing to do is to remove all of the homebrew modifications on the bike so you have a known baseline to work from.
Let me know if this is too smart ass for you.