ahhh the DL doesnt have easily removable arms? That looked a really good idea and at a glance did look like they would remove with just a bit of unscrewing.
If I remember, the DL arms have a nut and bolt on the clamp, but with a second nut welded onto the end of the bolt, so that it can't be removed completely for "security". You could probably butcher the second nut off so that the arms were removable.
I don't think that there is a great answer for what you're after: all the carriers on the market hold the bikes too close together for easy and faff-free loading of three bikes, although once you've figured it out once, it's quick enough to do it again. The only time I've carried three bikes, it's always two mountain bikes and a road bike. I suspect that three mountain bikes is always going to be a PITA with the handlebars.
I think pdw has it with the strava evo
I'd love to say the Evo was the ultimate rack. It's a very nice piece of kit, and is better than the Thule in all respects except the fact that the arms are the wrong lengths, and push the bikes closer together making loading that little bit more difficult:
Strada Evo (notice how close the second and third bikes are):
I've been in touch with Atera, but they can't offer an explanation for this bizarre bit of design. It's not helped by the fact that the Thule clamps compensate for the differences in frame tube sizes, but the Atera ones do not.
I stuck with the Evo for various reasons - boot access is much better:
The Atera fits in the boot (just):
and has some nice touches like the strap holder, and a slot to hold the electrics plug when not in use.
The arms on the Atera are a bit lower, but in both cases it's down tubes and seat tubes rather than top tubes.