Hi
I have tried your test app.
On my laptop i7, the jank is hideous.
On my moto g6 android 8 with remote preview, it has jank, but is a lot better.
On my moto g6 android 8 with apk, the jank is much, much better, hardly noticable.
C3 on chrome has janking issues with scrolling on some devices, even with tiny projects like yours.
I have asked about this issue before, and apparently the blame lies squarely with chrome.
With Microsoft now moving its Edge browser to a chrome based one, I hope there is some improvement in the future, as we will now be more reliant on chrome more than ever, I suppose time will tell.
Cheers.