If you are referring to the steel tray from Wolf, yes...
My tray is made from aluminum and allows the battery to sit about 1mm lower in the chassis. Those that have bought it can attest to how well it works. It,s a bit more flexible too, so it doesn't bind up the chassis as the steel version does.
I also made some shock tower spacers as well which helps to add some stability to the rear end.
I'll think about doing another chassis conversion now that I will have a way to produce it in low quantity without breaking the bank. I like the chassis mounted dual crank steering idea along with a new top plate.
As far as battery swaps go with the tray less design, I just roll off the side belt and slide the battery out sideways. No big deal...
Mostly I just leave the battery in and charge it between rounds. That's the nice thing about LiPo batteries vs Nickle based batteries.