There are already some fun modifier s like shears or collecting etc and of course the base modifiers art her as well like quarts.

But I think there is a lot of potential in a spinning weapon to have some interesting modifiers.
Here are a few I came up with:

Tangled: applied with a lead and fishingroad makes the yoyo pull the mobs it hit towards the player when it retracts (fun combination with sponge to move animals around)

Explosive: makes the yoyo do a small explosion when it hits something (everyone loves explosion if they don’t break blocks)

Digging: adding a vanilla pickaxe or TiC pickaxe head gives the yoyo block breaking functions as long as it hits a block

Spiky: adding prismarine shards or swords to it can give it a damage boost by adding 4 spikes to the sides

Bouncy: the counterpart to sticky instead of sticking to blocks it will bounce of of blocks makes it fun in narrow places.

Sling throw: adding a bow to it makes the initial throw super fast and pierce trough mobs or maybe chargeable to give it an initial damage boos on the first hit.

That’s it for now I found these ideas fun maybe they are doable and you find them funny as well Tangled is my favorite among them.

I do like a lot of those, thanks for the suggestion!
Bouncy and sling throw would be really cool, but I can't think of an easy way to implement them right now.
I did have working code for digging yoyos, but I never got around to integrating it with the rest of the mod.
Tangled and explosive should be very doable, though! After I release the next bugfix I'll get working on those!