First, I'm not a Boyd apologist, not a Boyd player to speak of. But there seems to be some clarification needed before you give up on a casino you've liked in the past.
I can't speak about the "point" conversion. My math skills aren't up to that.
Points versus Tier Credits:
"Points" accummulate forever until you spend them on food, etc. Or they expire in six months if no gambling action. This is pretty much the same as in the CET and MGM systems.
Tier Credits are what gets you into Ruby, Sapphire, Emerald, etc. Everyone's Tier Credits start over at zero every January 1st. However, if in the previous year you earned enough to qualify you for Ruby, Sapphire or above, you retain that Tier (not the Credits but the Tier) for the following year through December 31st. Again, like CET and MGM.
At any time during any year (e.g. August 20th) you have earned enough Tier Credits to bump you into a higher Tier, you "become" that Tier at that time, and through the rest of that year, and through Dec. 31st of the following year. That may be good news to some.
Your Credits zero out, but you retain the Tier and the benefits that go with it through the end of that year.
If Boyd has previously allowed you to build on your Tier Credits from year to year with no loss of credits ever, I can see how this will be an unwelcome change. Me, I would give it a chance, see how the points and Credits accummulate with my usual play. But that is each person's decision.
Hope this helps.