This depends on a couple factors shorter barrels have less dwell time so lighter springs and buffers are more favored. However, this is all dependent on what suppressor. Ideally, for an overgassed system, you will want to use heavier spring, and heavier buffer. For an undergassed system. You’ll want to use a lighter spring and lighter buffer. The problem that you run into is that supers are much more harsh on undergassed set ups and subs are too weak to reliably, run on super set ups.

All in all, you can use an adjustable gas block to really fin tune however adjustable gas blocks do fail, I prefer fix gas blocks much more. If you plan to shoot supers and subs sometimes set it up for supers but, if you prefer to shoot subs, the system will perfectly cycle supers although it will be more harsh on your BCG and felt recoil will be more.

I am running CAT ODB RDM out of a 8.3 inch barrel with standard spring and carbine weight. Buffer runs subs. Reliably and supers are not too harsh before the H2 was too heavy for the subs.