Berry trees can give non-Berry items (Generation II version) (short)
Read description for more information:
A very long time ago, bigsupes made this GameShark code for Pokémon Gold and Silver to turn Berry trees into item trees; 01??2ACF . Earlier, I tried to lock CF2A with arbitrary code execution, but unfortunately currently it seems the GameShark code is still the only way.
https://glitchcity.wiki/Pok%C3%A9mon_...
Also someone made this code for GameShark UBB, and you have to carefully use it in a specific way to avoid a loop.
"The Ever-Giving Fruit Tree (Author was known, but name was lost and post has since been
deleted on GameShark UBB)
912E61D1
Note: To use this code, walk up to a tree and talk to it. Make sure the switch is off. When
the message says "It's a fruit-bearing tree", turn the GameShark on then off. Repeat to
gather more berries. "
While in the GCRI Discord, I noticed someone had done this for Generation IV, so later I may show a video of non-Berry trees there (and try to do it in Generation III too).