Visual feedback of plugin type
It would be really useful to be able to see at a glance if a preset has the vst2 or vst3 version of a plugin, (or AU, or CLAP when/if it gets supported in the future). It doesn't need to be big, just a simple little visual in one corner of the area where the plugin name is shown in the layer page. It would make moving from vst2 to vst3 (or the opposite direction) plugins by fixing your presets much easier, plus it would generally be useful for a variety of other reasons.
I agree 100%. Unify v1.7 (I think) used to be able to display the plug-in type in the title of each plug-in's GUI window, but that broke somehow in v1.8. I like your idea of some kind of small icon in the plug-in box. I've added this to the to-do list, thank you.