While the right click menu is indeed intended for administrating tabs, it feels unnatural and represents an extra step to use split view feature. I believe a separate button on toolbar for tab split view would be much more intuitive and faster.
I think its really useful feature but placed way too far away from minimize button. It should be placed near it and icon changed into search one. I would keep Firefox View button near my profile button, or even better merge it with profile button alt...
