I hate to be that guy but if you aren’t comfortable towing with your tailgate down, you need to secure the machine better. Use chains and ratchet binders instead of straps for example. Two (one in front, one in the rear, pulling opposite directions) and cinched down enough to compress the suspension should be enough to carry you through any circumstances. Toss a third strap over the top for good measure if you want.
It may feel strange carrying it with no tailgate but secured properly it won’t go anywhere