HA! That won't happen, he has said many times he cares not for compatibility with ANYTHING. I reccomend trying the TMI Patch posted here. It works great for redpower2 items, since they all use such high damage values.
Hmm I'll decompile TMI later to see if there's any hack I can do to prevent crashing...
Also, I plan on making a new chest, Same size as diamond chest but block is transparent/invisible and does not collide (players can go through).
Is this a viable choice or are there other suggestions?
Basically, I can fit 4 chests into this 1 blockID, so I'd like to add a 4th.
if you got any suggestions, just post them down here.
Also, Personal versions of the chests will be added later on. Depending on the implementation, I estimate a new blockID to add the new personalized chests.
If requested, I will split the add-on into 3, a core part and others each containing a certain blockID block.