Yes the same concerns I have.
I'd love to go the lighter weight of the 2 stroke, but the low running noise, lack of smell and fuel economy (in terms of range, not cost) are very appealing.
Ratings for Rise & Fall brackets (for both 2 and 4 stroke motors) – standard shaft, up to 25hp (18kw), long shaft up to 20hp.
Maximum motor weight of 58kg.
So 10 Hp and 39 kg's would seem to be well within, decisions/decisions!