One nit: this should only take about 40 minutes on a Pi 5, assuming you're compiling with -j6 to use all the cores.
(Still faster to cross-compile)
Some guy on a German Linux forum thought my idea was an actual plan by the systemd team, and another poster had to correct him that the author was "FAKE Lennart Poettering", so the joke either didn't land or landed all too well, depending on your perspective...