Do you find the free-stroke adjustment actually works ok on the 8100 XT levers? I'm very tempted to buy some but I've read differing opinions and so have been holding off. I have SLX levers with no bite point adjustment and have small hands. If I set the SLX levers to where I can reach them they just about touch the bars by the time they bite.
No. I find it does nothing. Having experimented with this on different levers, I have discovered that the screw on SLX levers is as long as it can be. It is screwed all of the way in - making the free stroke as short as possible. I have tried longer screws and possibly got 1mm less stroke but ended up breaking one of the plastic pieces that pushes the piston in. They are fairly delicate.
TLDR: The SLX free stroke screw is already set at near minimum free stroke. As the XT free stroke screw comes completely tightened from the factory, it can be used to increase free stroke but not reduce it.
Regarding a Shigura setup. I have found the least freestroke to be with servowave levers and MT7, MT8 or Trail SL Calipers.
The quad seals are slightly different allowing for less pad retraction and therefore a shorter distance between pad and rotor. They are a pain to setup and keep from rubbing however. The MT5, MT4, and Trail Sports allow a little more room while still offering very little free stroke.
I have both setups and find if I'm being picky, I prefer the feel of the MT7/8/SL calipers despite the PITA setup and potential rubbing.
I prefer very little freestroke and run my levers on the close side as well. There is only about 10mm of movement (measured at the lever tip) before bite and no way I could get them to touch the bars.
May want to verify a good bleed.