Here’s a link to OMAAT’s website about LifeMiles expiring:
https://onemileatatime.com/lifemiles-expiration-policy/

It does not make it clear in the article if mileage “activity” is actual flying or if buying miles counts. If it still shows a March expiration date, I would guess “activity” qualifies as flying and buying won’t prolong expiration.

Can one apply for the credit card and accumulate miles that way to not get them to expire? It’s annoying that LM gives you such a short span for expiration.