Could you be specific about what you prefer about a cron job over a
systemd timer unit? If it's just that you are familiar with cron jobs and
not systemd timer units, I'm sympathetic but I don't think that's a very
strong argument for the additional complexity you're asking for. Other
software in Debian is already using systemd timer units, so you're likely
to have to become familiar with them at some point regardless. But if
there is some other concrete use case, I'd love to talk about it in
specific detail rather than just in generalities.