Why do you need a power meter for fixed? Theoretically possible but youd need to respace your hub or get a dished chainring. USE do some nice but pricey ones and I think wolftooth make a dished one designed for CX setups on MTB cranks
it isn't the end of the world if your chainline isn't 100% bang on. Using a Road chainset for fixed TTs is fine. I disc hub means you can't use cogs small enough
Why do you need a power meter for fixed? Theoretically possible but youd need to respace your hub or get a dished chainring. USE do some nice but pricey ones and I think wolftooth make a dished one designed for CX setups on MTB cranks