In our company our OKR periods are tertials (4 months), not quarters, and we use Goals for OKR reporting and status. So, would be a lot cleaner and more intuitive if we could use T1, T2 and T3 instead of Q1, Q2 etc.
A generic solution would be that admins could divide the year into how many periods they like, and give them whatever name they like, and that these custom date ranges was visible in the range picker at https://app.asana.com/0/goals/.