I find that cold steel imprisoning my wrists feels totally inescapable.
I agree leather cuffs are much more comfortable for long term wear and don't mark the skin as much as steel cuffs, but it is always in the back of my mind that they can be cut off, even when locked.
If you like the security of steel but don't like the marks....... (I think marks are great but if you need to be out in public soon after a session, the marks should not look like you just escaped from prison.)
Consider using a set of Darby handcuffs and leg irons which are not hard to get (but hard to get working right) or Medieval style wide cuffs or the older "Tower" style handcuffs and leg irons.
The Darby types are easy to find but often do not work very well until seriously adjusted and reworked. I have a few sets that are probably made in India or Pakistan and needed a lot of work. The sets from South Africa are much better made and work better but are not easy to find. I bought my sets at least 20 years ago.
For leather cuffs, we have a set by Humane Restraints which is very well made but also expensive. It is for mental asylum role play. They are secure, comfortable and quiet when rattling chains in the background is not appropriate.
We also have a couple other sets of lockable leather cuffs but don't use them much.
One set was actually bought at a charity event. I wonder who donated them? I bought the entire set for $1. The seller obviously had no idea what they were and I did not think it was a good idea to explain them to her.
So far, they have been used exactly once by us (They look pretty close to new) and I can tell you they are quite secure when a couple padlocks are added. If done right they are as escape proof as anything else made of leather.