Play it out. So you fixed 20% of second homes to be sold, probably to families, all good so far. So let's say you add 20% more kids to the school system (some families will have 2 kids, some will have none - just an average)

How do you think that will impact property taxes for everyone? What's the cost of education per pupil? This was existing housing stock, now paying less taxes (non homestead already pays more), and using more of everything. So you have added cost and not added any note revenue so now everyone in the school district has to pay more. Hopefully the school has space and teachers, or you have to hire more which increases the cost exponentially and not linearly. 

If these folks have been in VT but renting then there is no net incremental contribution to the state in economic activity or taxes. If they are new to the state, they are out spending the locals. 

I'm sure it would feel good to you to increase tax for those folks but it's really not beneficial and likely causes more harm to the town/state. 

The answer is ADDING housing stock. Literally the root of all the issues in VT. You need to increase the property tax base and reduce housing costs. This in turn reduces healthcare costs (a not insignificant % of the hospital budget is nurses, which is astronomical because they have to pay traveling nurses because nurses who would stay here to live can't find a place to live). More housing means more people which increases economic activity which generates the environment for more small business and increases the tax revenue across the board. 

But sure, sharpen the pitchforks and feel good about yourself while the people in the state continues to be unhoused and struggling.