I don't no, i think it is possible if i make a new Task API :3, but my eyes don't like to look at those task file
Depends on your use case. What do you plan on using it for? A separate thread is the only method to create a delay of less than the tick rate (50 milliseconds). But do note, even if you do use a thread you'll have to collect your data by a call to thread from the main thread so you're still going to end up collecting it as fast as a tick at the minimum. (AsyncTasks are "pinged" every tick to check if they have been completed). A pseudo-25-millisecond-delay strategy would be doing things multiple times in one tick. For example, if you plan to add 1 dirt block to an inventory every 10 milliseconds (which would be 5 dirt blocks every tick), create a task with a delay of 1 tick but add 5 dirt blocks to the inventory in one task run. P.S. This is basically how redstone "0 tick pulse" circuits work.