Wait there is someone who is actually catching them all? :O
I'm kinda trying, if it's worth anything.
Oh no! :( This means we can't get all Pokémon in-game, not even FE only forms. Honestly, why wasn't increased box space researched? Gen 4 sprites and models can fit in a Gen 3 cart, so why not the amount of box spaces too? Not to mention all the additional Pokémon we're supposed to be able to capture, yet... we can't due to boxes, which seems like an obvious oversight.
Can anyone make a PKHex of this game, so we can keep more Pokémon?
It's not an oversight, there's technical reasons why the amount of PC Boxes is not expandable.
You should join in PokeCommunity's Discord Server if you wanna know more about it, FBI (
a well-known ASM and C ROM Hacker) just talked about this topic.
As for your other question, PkHex is Open Source so anyone with the necessary skills and knowledge can do whatever s/he wants to do with it.
Does anyone know how to finish the relic beasts chapter???
As it was mentioned before, you can't because it requires Rock Smash which is not obtainable in the Beta 13 Part 1. Wait for the Part 2.