What I’ve learned from others on the forums, and then confirmed in practice, is to set in-game gains at pretty low numbers (say, 30 to 60 %), and then adjust the power of Simucube until I get the output I want. On rF2, for example, which is still a work in progress to me on FFB, it seems to work well to set the per-car multiplier at 0.3 to 0.6 and run the large Mige at 75 to 100 %.
Now, for AMS, lowering the gain does indeed help with soft clipping. However, there are some cars on some tracks (particularly some mod cars) which may still need adjustments to the individual RealFeel “MaxForceAtSteeringRack” to eliminate the soft clipping on high force situations. There are some pretty detailed threads on this and other forums on that topic. I would start, though, with simply adjusting the in-game gain. For example, it works well on my large Mige to run a full 25amps (100 %) on Simucube, and put in-game gain at 35 to 45 %. That is still rather stout FFB. For my money, AMS is the most rich FFB experience on a DD wheel, and needs very little tweaking. Driving a Formula V10 around Suzuka (Kansai) is one of the best experiencing in sim racing that is truly done justice on a DD wheel. It has all speeds of corners from chicane when the wheel is light to sweeping high-downforce corners where you can feel the wheels struggling for grip. So much fun.
I don’t claim to be a guru, but what it appears game developers do to account for the vast range of strength of wheels (from Logitich DFGT’s with tiny motors and big gears to the Large Mige with a big motor and no gears), is to shift the range of feedback upward so that small forces can be felt on weaker wheels, sacrificing detail at the top end because the game then “clips” off the top range when maximum output is reached. Shifting that range downward is feasible on a DD wheel because a DD wheel can relay even tiny FFB outputs to which a weaker wheel would not even respond.
Sorry . . that’s a lot of words. The sum of the matter is this: run the in-game gain low, Simucube gain high. Generally speaking.