@Nekron: I checked the loaded libs and they seem to be the same for Flatpak and SFOS native. So, can't tell on the basis of that and its not why Xperia X is slower than XA2

try to run

flatpak-runner org.kde.mobile.angelfish chrome://gpu

(until corresponding issue is fixed, have to start new angelfish for it). I have HW accelerated canvas, flash and few others (not all). compare X and XA2 and see if there is some major difference.