Normalizing on employee locale adds so many assumptions about the life and lifestyle of the employee and their market that are somewhat unfair to incorporate into compensation.
Our company is far smaller, but also been remote-first for almost a decade, and flat salary structure based on role (we pretty much have just IC, lead or junior) and fully independent of location was the best.
Since we have two founders living in the Bay Area and in New York, two of the most expensive cities, a comfortable wage for those founders should be good enough for anyone anywhere.
For our own simplicity, we aligned compensation on gross (pre-tax) pay, so the take-home is slightly different between regions.