Anything you can do to differentiate the PRT viewport icons.
Probably too late now.
We have discussed it before, but there was always something more important to do.
Will make sure it is on the Wish List.
I certainly understand the importance thing, even just something simple would suffice. Certainly don’t necessarily need a slew of completely different icons.
If I may offer a suggestion:
I understand that since the PRT loader scales as you drag, it would be a perfect solution, and at least if/when they are stacked they are discernible
I think you underestimate the effort to change the logo data. 
Sorry, that was supposed to say “it would not be a perfect solution”, reminder to proof read my post…
Admittedly, I have no idea what it takes to change it! I shall be happy that it is at least a wish then 
I sat down on my a$$ and created the logos for all PRT object types.
I went with a similar concept where the old logo is still used (with small tweaks) and a text is displayed at the bottom denoting the object type.
Each one had to be exported into a mesh format for the C++ code of the plugin, so I had to write a script to convert the MAXScript TriMesh to our representation.
The logo is hard-coded in the plugin, that’s why it isn’t trivial to modify.
Your idea with the offset letters was cool, but we have 4 public types already and some more internal ones so they wouldn’t fit. I wrote the full names using the full width - “PRT Loader”, “PRT Volume”, “PRT FumeFX”, “PRT Source” etc.
Thanks for looking into it Ya da man! and it still appears that if they are stacked that they would be something to easy click… very cool 