It's easy in onyx. We have a quickset setup to ahtonadd 1" of bleed - auto add a fold line at the edge of the print, and auto add a fold line at the edge of the 1" bleed (mirrored) And add grommets every 24".
Now you just load your artwork with no crop marks / bleed, and everything is auto generated for you. Doesn't matter if you throw in a 24 x 36 banner or a 48 x 240" banner.
Onyx quicksets are awesome... You can automate most of your workflow / file prep very quickly. Especially for banners and canvas and stuff, where you need specific bleed