I’d check with the manufacturers of both of the devices about using the bus tie down systems.
Since both of them are designed to be folded for transport, they would have to advise you how/whether to tie down/secure for buses.
From what I’ve read about the new rear facing securement devices, something as narrow as the Atto is to narrow to use with them.
My daughter’s manual wheelchair is designed for transit and crash tested. But, the back folds down toward the front, so it needs to be forward facing. It looks like the Zoomer folds that way also, so if it can be secured, it should face forward.
I would advise not to sit on either of those devices during the bus ride
I didn’t hear from either manufacturer and ultimately decided to bring the Journey Zoomer with me, and as luck would have it the first bus I took was a new one.
I was the first on, followed by a Go-Go and a Pride Victory. The Go-Go and myself were sandwiched in the new devices, neither of us had much drama or issue. I backed in myself, the GoGo needed assistance. The Pride Victory went into the old style hooks.
There was no issue with the machine, no complaint from the driver, it seemed to take the same amount of time between the old method and the new. The advantage seemed to be that we both could be activated and released at the same time which sped things up for folks.
My Zoomer flexes quite a bit. I feel the chair fleet on uneven terrain, the texture on the streets, and even as I pivot to get onto ramps. But I did not sense any significant pressure from the clamps which surprised me. It felt secure though, I didn’t have any rocking and at no point did I feel unsecured.
I did ask if I could sit on a normal chair and was asked to stay in my ECV. It was a packed bus, no incidents with folks falling but many didn’t know the chairs folded down.
The only negative part is I darn near fell off the ramp when I was getting off the bus, I needed two CMs to help me get upright. Talk about embarrassing!
Aside from that, the new bus was quite uneventful. I’m not sure if everyone just got used to them, or they dialed in the machines a bit more but it seemed to all work as intended.