My trigger spring falls between the HBI spring and the OEM spring in strength. So if for some reason the system did not work with my trigger spring, the OEM could be used.
My concern is not really friction - it ought not be that high because none of the rubbing surfaces are loaded that high (as opposed to the sear surface that probably has 5 or 6 lb on it from the hammer spring). The concerns I would want to look at are mass, as in how it would impact a drop test. When a gun is dropped, mass on one side of the trigger pivot impacts to make the trigger turn in one direction, mass on the other side opposes it. In the current trigger system, the imbalance is small enough that there is little tendency for the trigger to want to release when the gun is dropped. Adding a mass of a linkage can change that, so it would bear examination and testing.