Having the outboard cantilevered behind the transom (as with the B’n’B bracket) reduces the likelihood of the mainsheet tangling on the engine casing, as does relocating the mainsheet block from the end of the boom to a slider about a foot or so in from the end of the boom. One advantage of a bracket is that you can reposition the pad at the exact height that you want it, so as to avoid the boom clipping the engine casing. Admittedly you may have to replace the pad to achieve this, but that’s straightforward enough.
I bought a very cheap cover for my outboard – it has been compared with a shower cap, which I thought was a bit harsh – that I leave on the engine when not actually motoring. This helps to prevent the starting cord grip and/or the choke control from being caught on the mainsheet.