"I note that the blue custom is similar to mine (and I believe Joe's) in two ways - 1) no fancy Rivendell Custom lugs, just the standard Rivendell lugs and 2) a fillet brazed bottom bracket. I wonder if this is a result of Grant's evolving design philosophy - the existing stock of custom lugs no longer fit the new designs?"
That was my guess, especially for my case where I requested a rather specific "make it extremely upright for my dodgy wrists" design.* I didn't know what lugs I was getting (didn't ask) and found that the simpler design plus fillets look great with the grey/red paint I requested. Don't tell anybody but I'd love to do another one with one color and all fillet joints.
*Fun fact: I started with a pic of a RANS Feet Forward bike as a design idea, Grant thought I was crazy 😂
Joe Bernard