Do you by chance know what weight your eBikes are? Sorry for the impertinent question. The bike we are picking up tomorrow is 26kg and it’s looking like a pain to find a tow bar rack that clears and has specs for that weight.We have moved from the VW T6 tailgate mounted carrier to a tow ball mounted Atera Strada DL3. The main reason for the move was that you cannot open the tailgate when the bikes are mounted (and it is less height to lift an e-bike!) This was a pain on our travels when stopping in Aires and wild camping for a night.
We used the Atera Strada DL3 with 2 e-bikes attached on our trip to Spain and Portugal pre-Covid 19 this year. When we first got it I was concerned about the about of movement in the carrier itself. The curved slide mechanism adds to some movement. However, after using continuously on our 4,500 mile trip, it was never removed and did not budge. It was completely fault free and served us very well.
The DL3 is the bike carrier that gives you most clearance with a tailgate van. Especially if you are lowered as you have less height and, therefore, clearance to the ground to hinge back on.
Thule make great carriers (the T6 tailgate carrier is made by them) and I am sure it is more substantial (and of course with that comes weight). If I could open the tailgate with a Thule carrier, I would probably go with a Thule. But I cannot complain that the DL3 does not do the job and there are many happy users.
Real world experience might be better than lawyer specs.