I've had multiple bug reports for Elemental Shift where users have had the tinker crafting menu refuse to craft an item on the basis of insufficient cargo space when the player does in fact have enough space for the new item.

I have not yet replicated it myself, but it seems to affect random crafting items, and affects different items on different savegames. I do not know if it is consistent between different stations (I'm following up some of the reports to try to find out).

As Elemental Shift does not alter the core crafting system, and only adds recipes to the sovereign, it is highly likely that there is some engine bug underlying these reports.