I think the answer is probably "no", as I've done a fair amount of research and failed tests of custom annotation families, but figured I'd ask the question anyway. I utilize materials and material tags to the greatest extent possible for 2D and 3D/rendering representations of my architectural designs, and use material tags heavily in all views (especially elevations and sections) to take advantage of "smart"/ parametric annotations that will update if/ when materials change over the course of a project.
The way our firm uses material tags is somewhat generic, like "MTL-1" for "Exposed Exterior Painted Structural Steel", or "MTL-3" for all sheet/ brake-metal elements. By generic, I mean that there are a ton of different steel shapes in my project that are "MTL-1". Sometimes, when using a simple Material Tag annotation family (pulling the "Mark" value from the material definition), I want to be able to have an instance text parameter to add some clarifying information, like "TYP" for typical (so I don't have to tag the same type of element over and over), or "CHAN" to identify the steel element as a channel, etc. Sheet/ Brake-metal is another example--there are often a half-dozen or more descriptors I'd like to use on a per-instance basis for material tags in my drawings.
Point being that I realize I can create custom text-based shared parameters for materials, but these seem to inherently be Type-based, not instance. I want to avoid making gobs of custom text material parameters and associated custom material tags, and/ or having to duplicate materials left and right be able to tag "MTL-3, Gutter", "MTL-3, Fascia", etc. (for brake/ sheet metal).
I've tried to nest material tags into other tag types (no luck), or to nest generic tags into material tags, but cannot achieve my desired effect. I can of course just resort to a material tag and a separate dumb text note (per sample image below), but it sure would be slick to have an instance text parameter (with instance-based on/off visibility check-box) baked-into my material tag, so that at any point with any material tag, I could turn this text box on and type in whatever I want, without affecting any other material tags in the project. I tried multi-category tags, but can't seem to make those work to tag the Material:Mark parameter in my assemblies in my project file.
Any clever ideas to achieve this goal?!?
