I have 2 single captain chairs upfront from factory and added the 'Scopema' swivel plates. I'll share my experience..
If the Scopema swivels are 'the best overall' according to Faroutride.com then the others must be absolute dog*%$t. These bases weigh an absolute tonne, they add height to the seat base so if you are very tall then your headroom is compromised and the Scopema are the lowest around AFAIK. They creak and squeak even if you grease every nook and cranny. The procedure to swivel the drivers seat is a joke: Put van in gear, lower handbrake, pump seat all the way to the top height setting, pull seat all the way forward, with door open release swivel latch (which in itself is poorly located), then you can swivel whilst trying not to choke yourself with the seatbelt.
If you have the 2 batteries setup and inverter outlet below the handbrake like I did then good-luck with that!
More hurdles if you have heated seats as the cable isn't particularly long.
After doing all the grinding and replacing the handbrake assembly bracket I ended up ditching the swivel because I needed the room behind for the custom bench seat. When you rotate the driver swivel seat it takes up a stupid amount of room on rotation, so I would lose out on nearly a foot of precious campervan build space behind.
Negatives aside the passenger seat is an absolute doddle and easy to use so I can recommend that. The drivers side is a complete joke IMO..
I think there's an option on the Mk9 Transits factory swivels I bet they're a lot better.
So I have a Scopema Driver's Swivel plate if anyone wants it? You would just need to source the handbrake lowering kit.