I typically use a safety razor but also have a ton of experience with 2, 3, & 4 blade carts. Basically across the board I cannot have hair longer then a "no guard clipper buzz" regardless of what took I am using to mow it down. In terms of cartridges I do find that the 2 blade is much more forgiving on longer hair then the 3 or 4 blades carts. For DEs I've found I can maybe go one extra day if I am using my open comb because it does not clog up at all.
Also, in case any of you are not DE users, you go about a proper wet shave with a single blade differently then a regular cartridge shave. A proper wet shave calls for typically 3+ passes with fresh lather each time to promote gradual reduction vs immediate removal.