Maybe you could just try the drop dose, which is the easiest dose to measure.
To measure a drop dose you push the plunger in all the way. Then insert it into the pen or vial holding it in. Once inserted you release the plunger. There will be a drop in the syringe.
I would count have many drops are in your .25 and see if you can get half of that fur .10. Sometimes there’s so little you could go to a drop. Other times it’s more. It depends on the syringes used. Congrats on the reduction.
You can use an old syringe with colored water to count drops.