Will it do any harm to the 4 stroke to transport it at an angle roughly the same as it would be if in the up position on a transom. Motor will be on a stand and securely strapped dowm?
You did not mention make or model. That aside, it is generally advisable to tow any boat with the motor tilted down, to avoid undue stress to both the transom and the clamp, anless using a transom saver strut. I would suggest the same holds true is hauling in a truck, van, etc.
Just for grins.... Model # MFS20CEFS. When not on the inflatable, the motor is mounted to home made stand in an upright position. Both the motor and stand will be positioned (laid back on a supporting structure) in the back of the pickup truck at an angle which approximates the angle the motor would be if it were hanging off a transom in the up position (most likely more closer to vertical). My assumption is the issue with transporting the motor correctly is associated with the crankcase oil in the 4 stroke. Manual is pretty specific about laying it tiller down, transporting it upright or draining the crank case oil if it's going to be transported in other than these three positions.