Yeah, a spindle affords a lot more flexibility w/ ER collets.
In metric countries, there are more collets available than the standard 1/4" / 6.35mm collet which is standard in the U.S. — this seems to vary somewhat based on the standards of the country in question.
If you know someone in the U.S., or you’re willing to look at a shipping service you might want to look into the Elaire precision collets which are quite nice (I have both the 1/8" and 1/4").
The adapters work, but introduce another potential point of failure and additional runout as well as usually not being balanced in design (single slit) at the smaller sizes. I used one on a Harbor Freight 1/4" trim router for a while, but cuts w/ the Makita and Elaire collet are much cleaner.