I think top accounts have favourite creators that they curate, and they also find more good creators along the way.
With 19k HP it'll be difficult to keep your HP above 70% unless you don't use 100% when voting. I think there's no magic or hack to do it. If you constantly curate manually, you'll have your VP in the 50s.

However I think you can actually allow your VP to recharge for days, I've done that a few times.

You'll just have to make sacrifices when it comes to Curation