You're welcome :)

Unless you're testing admin typical tasks, like top navigation, for example.

And I suspect that active personal test wikis are never closed because Fandom staff use bots to spot inactive wikis. So if your wiki is never inactive, bots will never flag it for deletion.

That makes sense.

What else do they use bots for?

How long does a Wiki have to be inactive for the bots to detect?

"I am making edits to it and adding content to it."

Test wikis are not really to add content. It's to test stuff. Content should be added to the real wiki.

I've seen test wikis that are up for many years. They are usually not closed if they are used, and are used for what they are meant for.

Also, a test wiki is usually only needed to either test things that need admin rights, like edit CSS and other MediaWiki pages, etc., or to develop & test complex templates that need other pages, subpages, categories, or other things like this, which would not be appropriate to do on a live wiki.

To just test a simple page layout or regular wikicode, a user sandbox should do it. You can create a sandbox (or several) on any wiki under your username, like

User:Ianspace1/sandbox

So as long as I use it, the Wiki won't be closed?

Yes.

Ok.