Double Cut only works on certain blades IMO .... if you have a fully convexed profile you are better off with Satin because when it comes time to sharpen it you are going to loose the finish if you need to run it over the belt sander .... I did a NMFBM Double Cut and whilst the handle tang and pommel don't shine which is useful when the knife is sheathed .... the blade has gradually gone to a ghetto satin from use and cleaning and giving it some sharpening .... usually though you can get by for quite a while just stropping the edge before it needs a proper sharpening and the double cut finish thins out ....
So convexed edges like the NMFBM, NMSFNO and the SAR 8 will need topping up more than others such as a flat grind FSH or FBM if you want a double cut finish ....
I have never encountered a rust problem though with double cut .... rather the opposite .... I find it can help stop rust .... certainly on SR101 it helps .... Infi I have never had rust issues except when stripping a blade .... sometimes under the paint there can be a thin cover of rust ....
I have just done a Sage RMD and Sage NMSFNO today .... here are a few pics ...
The NMSFNO had a really tough coating on it and took about 3 applications of stripper to move it ....under this there was some light rusting ... however giving it a ghetto satin finish using a mix of belts solved that and satin Infi is very rust resistant ....
The RMD stripped much easier but under the paint is a powdered coating which I oil and then leave it to soak in .... then I can remove it on the blade with a sander without the dust clouding badly in the air .... the oil keeps it attached to the sander pad .... useful when it is freezing and you need to work indoors ....
For me though I like clear satin finishes on my small knives for food prep ... the powdered coating will last a good while though if you wanted to leave it on but then again there would be little point in stripping the knife if that was what I wanted ... however the powder coating lasts well on the handle and the lack of glare when sheathed is ideal for me ....