NSF Cache Increase of drop time

Using Xpages results in a large startup time (ca. 10 or more seconds) when the database is not accessed for more than 15 minutes. Within these 15 minutes there is a normal response time.

I expect that when the NSF Cache is cleared on the Domino server, the startup is large. Since I do not know an other option than completely rewriting the application without using Xpages, I would like to increase the drop time for the NSF cache. Is this possible and if yes how?