Suggestion: use transmute stones to transmute mats into other mats.

In essence upgrade lower quality mats to better/higher level ones or create rarer mats, including furnishing mats or trait stones/items, from other more ubiquitous mats. Also permit downgrading of more expensive/higher level mats to lower level ones with each transmutation requiring a different number of transmutation crystals with more 'complex' transmutations requiring more crystals.

For example to illustrate the idea, transmutation within the same subset:

enchanting Ta runes 100:1 for kuta for 'x' transmute stones.
enchanting Ta runes 100:1 for mundane runes for 'y' transmute stones.
iron ore to rubedite ore 100:1 for 'x' transmutes.
metal ore to regulus or refined metal to regulus; number of transmutes required dependent on ore/refined metal type.
raw wood to heartwood or refined wood to heartwood; number of transmutes required dependent on wood/refined wood type.
traitstone conversions (eg molybdenum to culanda laquer) for 'z' transmute crystals


For example, again for illustration, between different subsets:

enchanting Ta runes to heartwood for 'a' transmutes
rubedite ore to maple wood for 'b' transmutes (downgrade exmaple)
quicklsilver ore to culanda laquer for 'c' transmutes


Monetise with a chapter that includes a 'transmute' station for doing the transmutations or Q4 QOL improvement. Would probably require more or increased sources of transmutation crystals.

I don't really want to expand or provider a deeper exposition than I have in the remote chance the devs develop the idea or are doing so already so as not to presume upon their individual creativity.