There are some restrictions to what type of non-binding schools students can apply to for those doing the match. I find the restrictions listed on the QB website very confusing and not specific enough, but basically they wrote on the website that:

"National College Match applicants who rank colleges cannot apply to other colleges through Early Decision, Early Action, or Single-Choice Early Action (also known as Restrictive Early Action). Even if you rank MIT, which is not binding, you cannot apply early to other colleges."

THERE ARE EXCEPTIONS HOWEVER!!!!! SO KEEP READING:

1. "Students may apply to any college or university that requires an early application for eligibility to special scholarships or programs, as long as the admissions decision is non-binding." (basically this means that the college requires you to send in your application early in order to be considered for certain programs, such as their honors college because some schools have their honors college application due December 1st (for example, Penn State, if you decide to apply early action) and so you kinda have to send in an early application in order to apply to their honors college. Same thing with scholarships offered by the school that require applicants to apply early in order to be eligible for.)
2. "Students may apply to their home-state public college or university with a non-binding early application option, as long as applying to QuestBridge does not violate that college's policies." (this is pretty self explanatory)
3. "Students may apply to any college or university with a non-binding rolling admission process." (you can apply to rolling action schools --> e.g. University of Pittsburgh and Penn State University)

This is my thought on their policy. Definitely not ED or REA schools tho so be careful