Can I add virtual kerns

I have a common problem in some of my fonts. Lowercase letters kern to fit under T in light weights, but have to be next to T in the heavy weights. But in some instances the kern hasn’t moved enough and the crossbar of T overlaps the lowercase letter. Is there a way to fix this without adding a master? I don’t want to generate more working files and then edit them because that creates problems when I make future changes to masters. And it doesn’t fix the problem in variable fonts.

If two brace layers with the same coordinates could somehow be recognized by Glyphs as being part of the same “master”, and one could kern those two brace layers, that would provide a nice ui for dealing with things like @DunwichTypeFounders is pointing.
For this to be convenient, matching brace layers would need a better way to be accessed than it is now. For example if I select two or more glyphs with matching brace layers, it would appear in the layers list next to the master layers for global access, instead of having to select each glyph’s brace layer one by one as it is now.

The virtual kerning should be independent of brace layers.
But showing matching layers when more than glyph is selected is a good idea.

I understand the need to keep brace layers and kerning separate, I was trying to find a way to be able to set these virtual kern pairs with visual feedback. There is nothing in Glyphs right now that allows to preview something that isn’t a layer. The Preview panel? But how would that work?
In any case, I think if you’re implementing this, it would be really cool to be able to somehow have the same kerning experience than with masters, instead of, for example, adding numerical values to a text field that requires a back and forth of exporting fonts/check test doc in indd/go back to Glyphs to change values.