[Samsung Galaxy Tab S7 / S7 Plus Questions & Answer] LSS4181:
I've unlocked and rooted the device as I tried to look into the issue further so I can't really rely on Samsung anymore. I haven't really updated the thread since then as I've been busy and am trying to live on with the issue which I think it's just natural for touch screens to have issues and I really can't avoid such...

With Android 10 FW, the issue seems to be able to affect everywhere as I could witness them happening in home screen and in touch test apps. However, things become different with Android 11 that the issue seems to be constrained to the particular app/game and I could no longer reliably reproduce them outside, only in some rare cases.

Since the BUD2 upgrade, I noticed that the additional taps I used to have during swipe/flick actions mostly disappeared, indicating some form of mitigations. However, with BUD2 I had times where touchscreen stopped working almost completely. Nearly all taps were dropped during the period that I couldn't pause the game nor call out the navbar, until I held the power button that caused the game to lose focus (pausing it in the process), and then touchscreen works again. Either I have a faulty hardware, or at that particular moment there were no CPU cores handling the incoming touch inputs at all.

I'm still looking at what might be causing the issue, but the logcat is too bloated to read, and I still need time to understand the meaning of every line in the kernel dmesg I dumped while playing and experimenting.

In overall, the tablet's framerate is very unstable while playing. On games that limit themselves to 60fps regardless, the game feels janky despite the framerate shown on PerfMon stayed stable at 60. On the other hand, the same games looked very fluid on my SD845-powered Razer Phone 2. I'm starting to wonder, if SD845 is a perfect SOC1 example, and SD865+ being a perfect SOC2 example, for this testcase.

Although I have systemlessly removed GOS via Magisk, it doesn't seem to have it removed completely as there are some logcats coming from system_server mentioning about GOS (especially, a watchdog), just that it couldn't find the apk to reinstall/re-enable. Also, I noticed some kernel dmesg lines containing "Input Booster" talking about something like "Del Ib instance" and I wonder if it has anything to do with GOS (as GOS stuffs tend to call themselves Boosters, like Game Booster).

Still, I'm noticing something that might be affecting the system performance. One of the games I play on the tablet could normally manage to reach near 120fps in-game, but it falls to 30-40 fps ingame after the app loses focus (e.g. switching to home screen or to another app) for at least once. Setting Motion Smoothness to Standard (60Hz) in this case would only make matters worse as it further cut the framerate by half (that is, I have 30-40fps before setting to 60Hz, after that I only get about 10-20fps). It may be because of the game itself (that's based on Unity), but I'm not perfectly sure. For that particular game I need to force close it and run it again in order to make it able to reach 120fps in-game again.

I have used SmartPack to set the GPU on performance governor with power level set to 0, in order to actually keep it on 670MHz as otherwise it stayed on 305MHz most of the time which I suspected it might be the cause of the performance issues, but right now, I'm seeing little gain in video performance and I noticed that the GPU clock can still go down to 525MHz after a while, something which I don't think it should happen on performance governor.