does anyone know how strict transavia is about hand luggage weight?

Sorry I can't help with that airline specifically but I can say every airline and airport are so short of staff at the moment that I'd be surprised if there are spare staff to check it.

thanks for the reply, but you're a little late.
Answer is that they didn't weigh it at all. there were baskets to check if the luggage was oversize but I didn't see a scale at all.
It might have been under the counter though.

I would have liked to bring my laptop bag, but it weighs 1.5kg empty.