...Ah well I took the chance and 'up'graded...
lineage-22.2-20250621-nightly-pro1-signed.zip on June 1 security patch installed smoothly using adb sideload and MindTheGapps-15.0.0-arm64-20250214_082511) And we still can only select one keyboard layout, so no easy layout switching, for multilingual usage.
Will report back in some hours if it seems to have become usable.... ADD:
From 94% to 23% in 11hours, so 6½% per hour, so still completely useless!
Oh well back to 22.1 it is...😠