I stopped using canisters years ago, because they were not user friendly as far as maintenance goes, which lead to putting it off, and the canisters contributing to high nitrates
Sumps are just places to put stuff, I have used plastic barrels, old tanks, stock tanks, whatever. And as far as configurations, they are endless, media, pothos, equipment all go there.
And I don't use baffles in any of my sumps, just simply use filter socks on the end of lines to the sump, to catch debris, and put bio media in mesh bags and lay them on on the floor of the sump, near heaters, pumps, whatever.
If place things right, maintenance is a breeze, and lines from tank to sumps can be configured so that by closing a valve, old water can be sent directly to a drain, or outside making water changes effortless.
75 gal tank sump

overhead planted sump/refugium

barrel sump

40 breeder sump

With media in bags, its easy to pull out, shake debris out in a bucket of old water, and put back.
Fluidized bed emptying into a sump

4ft tall biotower, flowing from tank into sump

configurations are endless