What is the use of the "customisation" folder in jira-home folder?

[Svea Michel]

What is the use of the "customisation" folder in jira-home folder?

Is this folder only for backup to store customized config files before upgrades?

We are using Jira in ia a container via Podman. The container image is a standardized one from a provider. Customizations are done with ansible. For reasons I need to modify the cipher settings in the server.xml file. A modification inside the non-persistent Jira installation is useless because after a full restart of the container the files will be initialized again.
A possibility I've successfully tested is to mount the particular file from a persistent location to the non-persistent location but that could cause trouble when Jira is updated (aka new container image is pulled) and settings in the mounted config file doesn't fit to the new version.

I haven't found any proper explanation for what the "customisation" folder is. Would it be possible to store modified files there and Jira copies them automatically to the right non-persistent location when the container is started?

[Matt Doar _Adaptavist_ · Accepted solution]

I don't recall for sure but I thought it was some way to add info to a support zip, containing all the files that you have changed. That is, the files in that directory are snapshots, not used by a running Jira instance. 

[Matt Doar _Adaptavist_]

In a fresh Jira 10.0.0 local install I have the jira-application.properties where I set JIRA_HOME and a bunch of package-lock.json files from various core jar files