been searching if there's a way to do that but i didnt really find anything that properly reloads specific sprites without either not reloading the bottom part of them or not reloading them entirely

The Odd include #(CART HERE) command in the games code a game that uses
this is pico sonic

sorry if this sounds mean but i didnt really understand what you said

see reload() in manual
you can specify what part of the memory you read and write to

I agree with @freds72 and just wanted to add a few warnings about the reload function :

The artificial delay is the same regardless of the reloaded data size.
Because the sprite sheet is a 128 x 128 image stored line by line, reloading a single sprite without touching the rest would require 8 calls to reload, when a single call can reload the entire sprite sheet, or any number of contiguous lines of 8 sprites.
There’s also a limitation on what cart you can reload from : for a BBS compatible cart, you can only reload from the cart calling the reload() function. This is useful for example after a game over to get back the original state of the map that has been changed with mset during gameplay.

If it’s more sprites you’re after, you could have multiple sprite sheets stored as compressed string data in your code. Check px9 by zep.
Otherwise, please give more context so we can help you better.

to reload the map it's reload(0x1000,0x1000,0x2000)