For the LB rims, ordered some 700 x 35c GravelKing Slick Plus as road tires.. will see how those do.
For now though, got the new 650b wheels (Hunt Adventure Carbon) w/ 2.1" tires mounted. These are so wide...halfway to being a fat bike, it seems. They barely fit my frame, with maybe 2 mm clearance to the drive-side chainstay. Looking forward to trying them this weekend.