per player upgrades

[fossil jolt]

You could probably use schematics

Look up schematics on the skbee docs

[hushed berry]

that, but they are called structures
https://github.com/ShaneBeee/SkBee/wiki/Structure

[vapid epoch]

Can I like loop all blocks in an area and replace it?

[hushed berry]

Yes

[vapid epoch]

ok thx

[vapid epoch]

can i do that per player with poask ?

[hushed berry]

Do you mean that only the player sees the changes client side?

Or what exactly

[vapid epoch]

yes

[hushed berry]

Well you can show a block as another block with skript as well

But if PoaSK has an expression for that it's probably even better