The blade spins ok when in the 1/4 - although likely "tight." 🤔
Not sure what type of shim/washer would be ok with the dado stack. I'll be honest-I haven't used my other dado stack on this saw...ever. Funny as I used it on my Bosch contractor saw quite a bit (they had slightly different setup when using dado blades).
Bit disappointed as I like these with the flat cuts. Was headed to make some trivets when things came to a halt (literally 🙄).