I have a challenging service upgrade. The FPE panel has been subfed from twice. There are also at least 6 branch circuits that will not have enough cable to reach the new panel. Typically there are a couple of branch circuits that will not reach the new panel and I set a couple of 4X4's to accomodate the short cables.
I am considering a gutter. I know that I am limited to the number of conductors before I have to derate - that's not a problem.
I've installed an oversize box (8x8", 10x10", etc.) off to the side of a new panel to collect these short runs. I connect that box to the panel with a short length of 1-1/4" or 2" conduit. Upsizing the wire isn't an issue, as the runs are too short, and need to be spliced anyhow.
IMO it looks much more professional - and intentional - than a bunch of scattered 4x4s.
If you're able to share neutrals you can run six circuits in one conduit without derating. Use a double-deep 4X4 box for the splices, add a PC light for light at the service, and you'll have a professional look.