@efraimip I don't believe this specific plugin is supported anymore.
Does a tool like this exist now, or is it in the works?
There is nodebb-plugin-customize when you want to make quick modifications to templates or translations. Between that and Custom CSS in the ACP you can modify most aspects of your theme without creating a new theme or subtheme.
99% of all posts in the "nodebb themes" forum are questions - not themes (I found actually only 1 single actual theme in searching many pages of that forum)
Here are some themes I know of that I think are still maintained:
nodebb-theme-persona (first party, default)
nodebb-theme-lavender (first party)
nodebb-theme-vanilla (first party)
I like allot of what nodebb offers but it seems less supported now - and less plugins available - than a few years ago.
NodeBB has adopted many plugin features into core.
How do we easily customize theme now? Without putting dev hours into it?
I'm not sure what exactly you're referring to by "dev hours", but obviously you can't get something for nothing. Somebody needs to know how to use HTML and CSS, even with this defunct plugin.