The theme won't have any effect. The template will.
Basically all the HTML is stored in the database as templates. Every time a page is called, multiple templates are called and parsed by MyBB.
Plugins modify the templates by doing a search/replace on certain html tags to add things to them. For instance, in the index template, the header is included by writing "$header". If I wanted to add the words "Hello, World!" below the header, I'd search the template for "$header" and replace it with "$header Hello, World!"
So you should look for these replace commands in the script, and put the code into the template manually if needs be.
The warning is standard. Like it says, it'll copy the theme into a new one to save the master style. You can ignore it
Basically all the HTML is stored in the database as templates. Every time a page is called, multiple templates are called and parsed by MyBB.
Plugins modify the templates by doing a search/replace on certain html tags to add things to them. For instance, in the index template, the header is included by writing "$header". If I wanted to add the words "Hello, World!" below the header, I'd search the template for "$header" and replace it with "$header Hello, World!"
So you should look for these replace commands in the script, and put the code into the template manually if needs be.
The warning is standard. Like it says, it'll copy the theme into a new one to save the master style. You can ignore it
