Q: upgrade server on 10.11.2 to 10.11.4

I have a running server with 10.11.2 and consider upgrading to the latest built of OS 10.11.4 and Server 5.1.

However I am reluctant because I run filemaker server along the SERVER app and some Zulu Calendar app, all with Precursor.ca 's Reverse Proxy setup.

Furthermore I run the server volume on a RAID made with Disk Utility....hehe.. Which El Capitan also does not really like.

All just works fine.. so why change?

But then...

Any hints or suggestions?

Yours

Pierre