Is mirror modifier the only method to mirror UVs?

Just curious if anyone out there uses any other methods for mirroring UVs other than mirror modifier?

Unfortunately the UV editor needs some love from a programmer and this is one of the departments that it need the most help in. There is a mirroring command in the UVs menu that might possibly do what you want if your model is just right.
In theory you should be able to manipulate UVs in every way that you can manipulate vertices with the only restriction being not adding any. In theory you should also be able to export them in svg format and work with them in an SVG editor and reimport them back in as long as you have not added any nodes. Neither are currently in the works AFAIK.

I was playing around with different vert manipulation tools, but appears they are missing things like Active Element for snapping and scaling which is what I use in mesh editing. So I’ll probably use mirror modifier or I think there is an addon out there too.

It’s somewhat unfortunate because some some of my mesh is in parts so I’d have to seperate, delete half, mirror, unwrap, etc… for the various parts.

Will the UVs be retained after mirror mods are applied and all parts joined back into a single mesh?

I would also like the answers asked for in this thread. Thank you.

scale X -1