I agree Portland should probably have its own index.
It doesn't speak well that you need to be told which metro areas to add.
The US government had to address a similar issue and came up with a handy list of metro areas:
https://www.opm.gov/policy-data-oversight/pay-leave/salaries...
I find it a little odd that you would be so adamant about your compensation algorithm and not do basic due diligence exploring what others in the space have done in the space.
HN commenters shouldn't need to tell you what metro areas are missing - you should have proactively identified them.