I’ve learned how to open a Chromium browser in my big LCD monitor and another one in the 7" touchscreen. (raspberrypi.org/forums/viewtopic.php?t=245552, at bottom of page). This suggested a path to doing what I really want: lvgl on the 7" display, the normal Raspbian GUI on the big monitor. The emscripten package is advertised to be able to generate js from C and permit exactly this. But I can’t seem to install emscripten on my Pi4, because it’s built for 64 bits and AFAIK a 64-bit Raspbian isn’t yet officially released.
Should I wait for 64-bit Raspbian? Try to install emscripten some other way? Or is there some other way to get lvgl running within a Chromium window?