I recently used "our favorite airline" from Luton to Trapani &
I recently used "our favorite airline" from Luton to Trapani & Stansted to Roma Ciampino.
On the outbound at both Luton & Stansted (both earliest flights) Ryanair staff were weighing & asking customers to check their bags in the sizing gauge.
At Luton they were doing it at the gate & at Stansted at the entrance to group of 6 or 8 gates that are at the end of the long walk from the departure shops.
At Trapani they were also weighing at the gate. No sign of anything at Ciampino.
If you don't want to be checked, my advice is to arrive after the first wave, i.e. well-after the gate number is posted as the Ryanair staff have only a limited number of scales etc. & soon get fed up with checking pissed-off Italians. Particularly at Stansted where they are quickly overwhelmed by the rush.
If you are fortunate you may arrive at the gate area with some Poles, they are particularly stroppy & have spectacularly large & heavy hand- luggage & tie up the facilities nicely.
I am always a little overweight so I travel with plenty of big pockets & practise how much I can put on & get in my pockets before I go. They have to allow you access to the toilets to change so you could also stash some books or a bottle of water in there before you re-present yourself to the desk for re-checking. By the way they may ask to re-check any travelling companions so don't just stash your heavy stuff in your friends/partners (already checked) bag. They are wise to that!