Comment by Maxatar

I can tell you as someone who is a designated market maker on several ETFs in the U.S., none of this exists as a means of giving market makers priority fills. You're taking existing terms and misusing them. For example institutional order prioritization is used as a wash trade prevention mechanism, not as a way for designated market makers to get some kind of fill preference. Leveling rounds also do not involve exchanges, this is an internal tool used by a broker's OMS to rebalance residuals so accounts end up with the intended allocation, or cleaning up odd-lot/mixed-lot leftovers.

I am getting the feeling you either are not actually a quant, or you were a quant and just misheard and confused a lot of things together, but one thing is for sure... your claim that market makers get some kind of priority fills is factually incorrect.