I want to share these videos with you. I hope they can be useful for you.
If you have questions, just write. I'll try to answer as soon as possible.
To increase the inertia we need more weight. Nothing better than some bronze washers for this purpose.

Just to show you new and used models.
In the used ones we can see 3 details.
1 - the diameter decreases
2 - height increases
...and most important...
3 - The density of the disc increases and the outside becomes softer. That's why the plastic washer should never be fixed or glued, allowing the percussionist to continue giving pressure to increase the dynamic range of the stick.