Hi just a minor nitpick - I've used devices like this, and one major complaint about them is that the tips of the Wacom styluses are incredibly fragile (about as bad as pencil lead).

It has been a recurring issue for me that they got damaged while traveling with no way to easily replace them.

If you could engineer a way to protect them (like a proper cap or a clicky pen mechanism) that would be a very handy improvement.