There are a few things you can’t do with Revit’s “Select All Instances” tool
- You can’t select all instance of one type and then all instances of another type and combine them into a single selection set
- You can’t select lines
- You can’t restrict the selection to all instances in the active view
To solve these limitations, try the new FREE Select By Type tool in the Boost Your BIM Terrific Tools.
If you enjoy using this and the other free tools and educational resources from Boost Your BIM, drop us a line and let us know how you’d like to make Revit better and support our work on Patreon.
Boost Your BIM 
I thought I’d give this a try in R2020.2.8 but it doesn’t seem that any of these work with the R20 api.
Do you see the tools in the Add-In ribbon?