The ME Level Maintainer is used to maintain some quantity of an item in the ME network. This is accomplished by requesting autocrafting for items that fall beneath a certain quantity threshold.
I know this already exist in this mod: https://www.curseforge.com/minecraft/mc-mods/lazy-ae2

But I really would like an Implementation in your mod with more configuration options, or maybe it could be added to an existing block ?

AE2 already has a variety of tools for accomplishing what you want without having to add any new functionality.

Interfaces can stock items, which can in turn be storage bussed to expose their contents to the network. You can use a crafting card to trigger crafting requests for those items. As of the v54 versions, you can stock quite a lot of items in interfaces (512 per slot by default, up from one full stack of each item in previous versions).

You can also use level emitters to send redstone signals to machines or contraptions which passively create items or fluids. Most mods have some manner of using redstone to control whether a machine will run, or whether things will be moved to that machine.