Here is a post by Letterbomb in his discord detailing 100%
Also here is a map he made https://imgur.com/a/S46X0o7
To quote him
"Items for 100% Completion:
10 Hearts, L1 Sword, L1 shield and Mirror Shield, Bow, Silver Arrows, Boomerang 1 and 2, Blue Mail, Red Mail, Bombs, Fire Rod, Ice Rod, Lamp, Bug Catching Net, 2 Bottles, Pegasus Boots, L1 Gloves, Flute, Hookshot, Moonpearl, and all 3 Pendants."
However, I could not find the red mail and the map does not have it. Additionally you can, without major glitches find the ether medallion due to reentering the agahnim fight and getting what would be the red pendant (which happens to be ether).
Considering this ether does nothing and it's quite a stretch to get this (also this clearly is not developer intended), it seems odd to add it to 100%, but in my opinion it should still be a part of the 100% rules. I think in general in ALTTP romhacks this should be the general spirit.
...
To sum up this post, ether can be attained without major glitches, however its clearly not intended and I think it should be in the currently not defined 100% rules.
so i did copy that list and add ether to it. I already saw that the red mail should be available at a secret ending (saw the discord message :D )
I hope thats a good solution for now.
