+2 for transoms.
I had an adjustable Plastimo stainless steel outboard bracket on a Zodiac Pro with a Tohatsu 3.5hp and it rattled like a Vauxhall Viva going down a gravel driveway!
Once the Honda 5hp is on and it's tilted - is there someway to secure it while underway? The tilt mechanism on most small outboards isn't robust enough for the kind of vibration and shock that will be likely when underway. I've secured my Mariner 4hp (2-stroke) with a ratchet webbing strap (through the engine cowling) to a stainless-steel U bolt screwed to the transom leg support. Works for me and is solid as a rock.