I've been able to change the reinforced fist's registered tool to a golden pickaxe. This works swimmingly. Attempting to change it to pickletweaks' golden paxel doesn't seem to work though.

I've tried forcing pickletweaks to load before cyberware by renaming it, but that doesn't seem to change anything.

I've also tried changing it to match Thaumcraft's Primal Crusher with no results. It sets the default to an iron pickaxe.

The weird part is that the plasteel fist in ReWIRED works, although the public code doesn't look like it should.

I don't see anything that looks like it shouldn't work, but when I actually try it, I get the fallback message saying it can't find the id of the tool I put in.

Upload your logs on gist or pastebin, along with the configuration you're using

Golden Pickaxe:
config https://pastebin.com/s4PE1Rvd
log https://pastebin.com/B0V0WxjQ
Golden Paxel (requires pickletweaks):
config https://pastebin.com/EvHWdJ7c
log https://pastebin.com/QrH4HYRf
Note line 683.
Here is the config I use for ReWIRED, which sets its plasteel fist to a diamond paxel and works correctly: https://pastebin.com/89GLqjiA

what makes you think the code shouldn't work?

Renaming with a aaa or zzz prefix has more chances to work than a simple number prefix (i.e. digits are necessarily before or after letters).
Either way, I've delayed evaluation of the configuration to the first use, so it shouldn't be dependent on other mods loading priority anymore.

Confirmed fixed on my end!