I have riden the b67 for 45 mile and it is a massive improvement,no more dead leg and lower back pain .Hopefully it will be fine and get better.
Next is some handle bars .
Saddles are very personal. You can spend a lifetime trying to find the perfect match. I’ve recently invested in an SQlab 160mm one, not cheap, but so far outstrips the c17 cambium saddles I’ve been using on my fleet for comfort . The SQlab doesn’t destroy my shorts either.