Taxing non-producing mineral assets would be an absolute nightmare in Texas. From my experience here, it would be a net revenue loss for tax payers, as it would cost large counties like Tarrant (Fort Worth) more money to determine the ownership, than the taxes it would potentially generate on non-producing minerals.
Kansas is a county-by-county state when it comes to taxation of minerals and royalties. Some counties tax non-producing minerals IF they are severed from the land, and other counties do not. I'm not certain, but I wouldn't be surprised that a few counties there do not even tax producing minerals or royalties on production.
Buddy, I will be keeping an eye on this issue, thank you for mentioning it.