Custom collision Entity/NBT

I have been thinking about this for a bit. And i have to say this would be one of the most creative ideas. How does this work:

Entity: You can summon a custom entity. The entity allows you to have an invisible collision which you can modify. With nbt you should be able to modify what can and cant go through the collision. You could also modify on which sides the collisions would be and how large it is. As example you could have things like a 1 way hall meaning u can go in but not out. In addition you could also add extra nbt to get the texture like how soul sand slows you down and ice lets you slide.

NBT for block display: As addition to this there would be a nbt something like {SpawnWithCollision:} which you can turn on and off to summon collisions at the block displays with the same warpings as the displays.

Why should this be added: This would give map makers and creative people to allow for all sorts of custom blocks with their own collision without having to mod the game. Allowing for larger vanilla projects that could only be done before with mods.