Could you give a specific example of how this would work? This is a blocker for the Observability team currently who are looking to add support for 24.04 to the grafana-agent subordinate charm.
Where would you envisage the two charmcraft.yaml files living, and how would you run charmcraft pack for each? Would you recommend leaving the existing charmcraft.yaml and adding a new directory charmcraft_24.04 with its own charmcraft.yaml and then running charmcraft pack --project-dir=.. to build the charm for 24.04, for instance?