Making a dedicated suppressed rifle with small port has been done for decades. What has been done many times to make a dedicated suppressed rifle with a small gas port (without going to a custom made barrel), is to cut down a 14.5" or 16" barrel that has a .063" gas port, then attach a suppressor. If this is what you are thinking, this will work but you may find that there are variables that come into play that may cause you to have to readjust things.
How a rifle and ammunition performs is based on many things like the three types of ballistic considerations of internal, external, and terminal performance. The type of ammunition used will need to be taken into account, as there is a huge difference between .233 and 5.56 when timing a rifle. There is also a difference between manufacturers, and specific loads. A suppressed rifle if being used for LE/MIL duty purposes should be tuned and zeroed for their duty ammunition and not training ammunition if they are different, and done so in the environment they are being used.
The environment that the rifle and ammunition is being used in will also come into play, as there are things like cold and hot weather that effects ammunition performance, and altitude as well. Take a look at many of the competition shooters that have race guns that are specifically built to run light loads, so they get almost no recoil. Then you see that same shooter and race gun on a range where the weather has changed, or the range is at a different altitude, and they are experiencing a gun that is now become unreliable in cycling.
So if you live and shoot in a place where the weather is the same year round, and you shoot the same ammunition always, you would be fine with a dedicated smaller gas port. If you live where you see snow in the winter, and hot summers, then a small dedicated gas port may not be the best option imho.
My personal preference is to keep with stock sizes of gas ports like .081" on a 11.5" barrel, then if needed I can always change out buffers or action springs to retune if needed. The traditional baffle stack type suppressors keep chamber pressures swelled longer, so you often times have to slow the unlocking cycle. When using the flow through type suppressors like the OSS, we find that we don't need to adjust timing cycles as we are not experiencing back pressure like on the baffle stack type suppressors.
CY6
Greg Sullivan "Sully"
SLR15 Rifles
TheDefensiveEdge.com
(763) 712-0123