Bitsyncom should just refund everybody who so requests and be done with it like any respectable/responsible company would.
Much easier for everybody, even them - no drama.

The situation would ofcourse be different if the product wasn't with DIY costs as expensive as a house, nobody would care less about a few weeks late delivery.

Lead-time is a lead-time.
A lead-time is promised. Shipping happens after lead-time.
Lead-time gets missed - grounds for refund and cancellation of order becomes real.
This is basic business 101.

Next Tuesday we already exceeded the 10-week lead-time even with our order.
Ofcourse refunds would not be allowed during the lead-time period, that's a given.
This should be a no-brainer.

Calling a dog's tail a leg doesn't make it a leg, no matter how hard you try to explain and distort the fact.