I have the old metal grots, and use a battlefoam 27 tall figure sword bag tray. That being said, most of them take up two spots, except for the folded wing sculpts. No idea how the plastic ones stack up. The assassin goes in pluck foam with the heavies and other “problematic” sculpts, such as the Bloodseer.
I magnetized all my models and will never look back, especially with legion snd all the wings. In my region maybe 20% of players still use foam. Ihere is really no reason for it anymore, exept if you want to transport your models by plane maybe.
Really, the plastic ones are gorgeous but nearly impossible to play with due to their absurd over hanging parts. Much like Neraphs and Seraphs. Easy play would require modifications, probably tall flight bases to ever be able to play reasonably. Then you would have to weight the crap out of the base or they would fall over constantly.
Or you could just play Primal Terrors and ignore all this entirely.