I credit to OZ (Asiana) for the easy Diamond at 40k in 2 years (which gives *G). Mileage expiry is 10 years for general/Gold members and 12 years for Diamonds and up. However, no CC transfer partners, although transferring from [Marriott] is a possibility to avoid orphaning miles. Lifetime Diamond at 500k is a solid benefit but I always recommend against factoring in lifetime status when choosing an FFP.
There are a lot of 50% and 0% credit economy classes, though, so really have to pay attention to specific carriers and fare classes:
https://flyasiana.com/C/US/EN/conten...alliance-miles
BR J does credit at 1.25 (all classes) so a HKG-TPE-SFO r/t will almost get you halfway to 40k.