Do that, and then book with SQ.
Can't book SQ with the United miles I created through nights and flights...
With a valuation of 1.4 for UR and 1.9 for SPG, these seem to be my options:
UR to United - 90k but no YQ, and takes advantage of my small United balance = $1078
UR to SQ - 75k + YQ of about 130 it seems = 1180
SPG to Aegean - 48k + YQ = 1042
SPG to Marriott to United + top up with UR: 37.5k + 11k UR = 866.50
I'm booking two tickets but these numbers reflect cost per ticket.