Thank you for the insight dvs7310 guv1976!

A good number of my US domestic flights are on a separate ticket - unless it's my connection in or out of the country. Which would be an argument for IB - but sounds like I'll need to do some more planning and calculating with potential trips.

WY flights I will need to look into - and yeah, if I book C then it's always low/discounted fares (when I can plan ahead) and Y+ are the trips with less lead time so it tends to book into higher fares..
I'll do some calculating with AA (though I think its out due to the domestic lounge situation) and AY - though IB looks like a good one.

Good thing is my SQ status year is Dec 1 to end of Nov, so my Xmas flights will account to SQ*G requalification already. So by the time I'm back from the holidays I'll already have close to 50% done, add in the trip in Jan/Feb/March and I should have achieved requalification already (or almost) and can go for OW status after.