Very nice/beautiful old-style lugged frameset . . . with 21st century improvements in componentry. A combination of craftsmanship/artistry!
We were owners of 2 lugged 531 tandem frames: Assenmacher in 1976 and a Colin Laing in mid 80s. Now have a carbon fiber Zona with, you guessed it: c/f cut-out lugged frame.
Puzzling on why you ordered a custom tandem and had never mastered the tandem riding technique before investing lotsa $$.
Learning to handle/ride a tandem is not too difficult, really.
The independent coasting could throw off your starting up a bit, 'til you get used to it
Pilot mounts tandem first, holds both brakes and keeps both feet flat on the ground. Stoker mounts
tandem and clips in. Seeing that you have IC, there's no need for stoker to pedal backwards and bring up pilot's pedal to the correct start-off position.
Make sure stoker does NOT try to steer, or look over pilots' left or right shoulder . . . sort of sit still like a sack of poatatoes (that pedals) 'til you get your act together after a few rides. A bit of a learning curve, but not bad, you'll soon get the hang of it.
Pilot's responsibility is to call out everything he's doing on that tandem, so stoker can hear it. Pedal, coasting, braking, shifting, stopping/slowing/left or right turn. Stoker does all the signaling so pilot keeps hands on the bars. Also pilot will call out all the bumps . . .stoker can't see 'em and is best forwarned.
Stopping the tandem; call out stopping; pilot puts both feet on the ground holding the brakes. Stoker dismounts and says "Off" after she/he walks away from the bike. That way, no unexpected karate kick by pilot to unsuspecting stoker.
Good idea to keep spouse of the Brown Tandem 'til you learn how to handle it properly . . . then have lots of patience!
Pedal on TWOgether!
Rudy and Kay/zonatandem