Thanks! It shoots great.

And yeah, if I'm doing smaller parts I'll drop the layer height down a bit on the 0.4 nozzle, or swap over to the 0.25 nozzle and drop it way down for the really small stuff. Most everything I do is large enough that I just stick to 0.4/0.2 though. Layer height around 50% of nozzle orifice seems to be a good place.

This right here. As long as your layers are bonding properly and everything else is equal, layer height is not a major factor in strength. I usually use 0.2 for most everything, and fuzzy skin to give the impression of print quality. Seems to work reasonably well:

https://i.imgur.com/OXWCyHJ.png

You'd need to adjust your slicer at minimum. It's always a good idea to calibrate for all your nozzles though. Sounds like it's time to get some more filament regardless.

Maybe swap to a 0.6mm nozzle. Lots of filaments with additives (glitter, CF, etc..) like to clog up on 0.4.