There are no federal limitations. If any of the 94 districts impose a limitation, it would be mentioned on the Unclaimed Info page of their website. If you are a subscriber, you can access that page for each district with the icon named “Unclaimed Info for District”.
It looks like this:
However, when we created this website (we completed it in March 2020), as of that time, there was never any mention of limitations in any of the districts.
We also deal with the surplus money from tax deed sales (https://www.SurplusDatabase.com) and the Asset Recovery Specialists who are our clients typically start at 40% to give themselves bargaining room. Since we look through the official documents quite often, we do see an average of 30-33%.