Well done Artur, and Mrs K, great race report and organising.
Flying mounts, for me is, totally dependant on race distance, type of transition, a muddy grass transition can clog up cleats, but running on a Tarmac surface is ice skating, and if you are mid mount, as someone else tries the flying mount and gets it wrong, say hello to the Tarmac.
For me as IanM says, T1 finishes when I am up to race speed on the bike fully clipped in, not still fiddling around with my shoes and position. But, if you are happy with the way it is done, then that is the best way.
Well done again, cracking time