I'm starting to use Upfront more and more... I figure, I pay for the membership, so I should use it as much as possible!
I'd rather like to start from scratch most times, but the trouble with that is having to build out all of the layouts, one-by-agonizing-one. Therefore, I'd like to use a Starter Theme, but I want to customize it, and not have to worry about WPMUDEV theme updates possibly conflicting with it in the future, or overwriting my modifications.
I have tested the following modifications for installing a Starter Theme on my site, downloading and modifying it, and then uploading it again, and so far it works well. That said, it would be entirely possible to make more new themes for use as "Starters", but at the same time, it speaks for the need of a tool/function from WPMUDEV in Upfront which would be something like "Create a new theme from a template theme" and it would automatically copy and modify the theme files as needed.
1. Install desired starter theme
2. Go to Upfront -> Builder
a. Hover over desired installed starter theme, click the download icon.
3. Extract all files to a folder
4. Edit functions.php and style.css:
a. In functions.php, carefully search and replace the name of the starter theme with the name of your new theme.
b. In style.css,
i. replace all URLs with your own,
ii. set desired new name
iii. update version number to something like 5.0.0
5. Now zip up your folder with the two changed files and name the zip file in the form of theme-name-5.0.0.zip
6. In WordPress, go to Appearance->Themes and upload the zip file as a brand new theme.
Please let me know what you think, or especially, if I've missed something that will cause a problem!