It seems you have correctly diagnosed the problem. But hey, 1h not enough for formatting, that's weird! How large is that volume?
The timeouts are hard coded unfortunately. A possible workaround would be, if the volume is relatively empty, to shrink it during conversion, and enlarge it after that using, e.g. resize2fs (I hope it is a logical volume).
I'll see what could be done to avoid such problems in the future.
Regards,
Plamen