A lot of this discussion is useless without examples. For under-the-enlarger lens diffusion, results can look like this. This may be 'glow' to some.
In my own work I have obtained what I would call 'glow' with a 50mm Planar 1.4 used at 1.4 with T-max 400.
I also get what I call glow with a Minox and Lith printing: