Convert Kerning to Group Kerning

How to do this, for example,

T @MMK_L_U kerning
but want to convert it to

Is there a method to do this or is it a matter of

creating @MMK_R_T @MMK_L_U kerning and deleting T @MMK_L_U ?

This is what Compress Kerning does.

I can’t reliably use this because it doesn’t print a result, I’m taking over some old files and there are situations where a base group pair doesn’t have kerning and there is a kerning exception which should not become the group kerning… so I need a more refined scripting way to do this

With such specific needs, why not write a script yourself?

Check out font.kerning in the docu.

I am writing a script… just wondering if there was a method to lock already, like an undocumented one like setRightKerningExeption_forLayer_