We’ve always recommended to preferentially use the CLI for plotting on the Pi and to try and avoid Inkscape there. Given that the differences are getting stark, I’ll start recommending that more strongly.
It looks like the RPi hardware is 64-bit compatible, but the OS is lagging behind (see, e.g., https://forums.raspberrypi.com/viewtopic.php?f=117&t=275370 ).
