If you put one of the Inferium-line Paxels into an Enchanting Table (or with an enchanted book on an Anvil), no enchantments can be applied.

I don't claim to know a lot about this, but in what troubleshooting I've been able to do, it seems like an issue between the tools and enchantment registries.

Versions (please complete the following information):
Part of FTB Endeavour 1.3.0 modpack

• Minecraft: 1.16.5
• Forge: 36.1.4
• Cucumber: 1.16.4-4.1.9
• Mystical Agriculture: 1.16.4-4.1.7
• Mystical Agradditions: 1.16.4-4.1.5

So it is done that no Paxels, no Tools from Mystical Agriculture/Mystical Agradditions, can be enchanted

P.S. I did also test this with regular Paxels from Mekanism, and in this modpack, they seem to work fine: