Sorry for the delay in a response.
Anytime one can use the newer Rust-Oleum ingredients they should do so, be it for RS-MM or Silver Fire.
That goes for using the Rust-Oleum Ultimate Matte Polyurethane.
Although mention is often made about some choices having been made because of availability, that is the least considered factor.
It's all about making improvements in the Mix by using better components. So use 'em if you can.
The Wagner listed on Amazon http://www.amazon.com/Wagner-0417005.../dp/B000DZBP60
............can be used "as is" with particular care to observe both distance and speed. With it's 1.6 mm nozzle, it lays down more paint more quickly, so speed across the screen surface should always be in the 3' per second range. Such thin "Duster" coats dry quickly, so it should not be too much of an ordeal if 7-8 coats need to be applied to effect complete even coverage.
(...but, if you haven't already purchased the Wagner, get this Puppy:
1000ml Electric HVLP Air Spray Gun Kit 600W Motor Paint Sprayer 1.0mm Nozzle DIY - - Amazon.com
Dusting has it's roots in the older S-I-L-V-E-R application, another extremely loose, wet mix that also depends upon a great deal of translucency.
There is no doubting that Silver Fire has almost infinite adjust-ability, so it is of obvious advantage when dealing with ambient light of varying degrees. It is ideally suited as being great for both controlled lighting in Theaters as well as ambient light that comes into play. It also excels at providing a real boost to Black levels on screen that come from PJs with less than Interstellar contrast specs.
RS-MaxxMudd -Standard- is a modestly performing Ambient Light Mix that has both the former going for it as well as excellent dedicated Theater potential. RS-MM-LL is almost always considered as being for dedicated Theaters and PJs with exceptional Contrast specifications...although it too can help improve the depth and quality of Blacks and Shadow detail to an extent that no Matte White surface can.