Members are not allowed to get more than 5% of the total units, which means a soft max of about 12000 right now.
It is feasible to reach a level where your pending upvote balance grows faster than we can deliver for your posting frequency. If you are considering high levels, we encourage you to read all the helpful readings and get a good understanding of how everything works.
https://steemit.com/steembasicincome/@steembasicincome/helpful-sbi-resources