Four point lift or low level trolley jack is the way to go. Some have used an adaptor with a trolley jack for the jacking points, but I don't even trust that.
I made an adaptor with a hockey puck, but I only use the cross members with my trolley jack.
It is a bit ridiculous that a company like Peugeot can't work out that the flimsy jacking points on the RCZ are not fit for purpose, and instead continue to blame owners/third party garages for incorrectly lifting the vehicle as the cause of the regular and continued damage to the sills by simply using the provided jacking points.
It is very unlikely that they will change their opinion on this matter, especially as they no longer make that model, so it appears that the only course is for owners to use alternative methods of lifting the car whenever necessary, to avoid further incidents.
I have read on these pages that Peugeot dealerships have said that they have used the jacking points many times without damage, so they must be OK.
That is a bit like the guy with an air rifle shooting at a gas canister, saying "I've shot it several times and it hasn't exploded once - therefore it must be safe to keep shooting". He would probably be correct, right up to the point where it blows up in his face.
If you have no alternative, and you have no option but to use the jacking point with a scissors jack, make sure you use the correct jack - one with a slot for the flange to fit into, and proceed with extreme caution, leaving it in an elevated position for as short a time as possible. Even then, it appears there are no guarantees.
Good luck with your repairs.