How to get 4 cables into this CU?

Metal CU has clearances of:
top 4"
bottom 4"
right: 0
left: plenty, but the tails run up there.

A christmas-tree cone bit is at least 2" long, leaving little space for a drill for top or bottom.
Right is possible by drilling through what it's up against, but the result would look lousy.
Left there's enough space in theory, but a lot of hand held drilling with a large bit very close to tails? Not loving that idea.
Looked at cutting into the front edge rather than using round entry glands, but not seeing fireproof grommet strip anywhere.

Suggestions welcome!