Medical research is a necessary part of finding a cure for any disease. More funding is necessary so scientists can not only look for ways to prevent brain injuries, but also so they can be innovative and find cures for otherwise uncurable injuries and diseases. Funding can include studying and developing gear that protects from potentially fatal injuries.
Any money given to researchers who are trying to find a solution or cure for existing brain diseases is money well spent. It is believed brain diseases will get much worse over time as the current population ages. If we can fund projects or initiatives that will help us eliminate these diseases, or greatly reduce their existence, we should have no problem doing so.
I think if you are a professional sports player you already know there is a risk. You take the risk by playing. It's your choice. However a domestic abuse victim does not. So for them I say yes but all professional players, at risk, by choice, should be required to give a percentage to the research.
Brain disease researchers should not be given more money to find a cure to CTE. CTE is detectable only after a person with the disease dies. More money and resources should be spent on finding ways to prevent the onset on CTE. Preventing CTE, and most other diseases, is cheaper than curing it in the long run.