In Xojo's current state, it is impossible to support both API 1.0 (pre 2019r2) and API 2.0 (2019r2 and later) in a single set of code.
My plans were - and you can see some of this on the GitHub repos - to update the classes for API 2.0 as the new baseline. That means if you wanted new features, you'd have to upgrade your Xojo version. The older API 1.0 classes would remain available, but would not be maintained.
However there are rumblings of changes coming to make supporting both APIs more possible.
So at the moment, I'm taking a "wait and see" approach. All development on my modules and controls is paused for now.
Moving Forward
I intend to open source my Zircon controls. They don't make much money, so they don't get much of my attention, and so I'd feel more comfortable if their source code were available to everybody.
I do intend to modernize the controls a bit. I'd like to support dark mode, as well as things like additional style choices for ZirconSwitch. To do that, Artisan Kit will need some system color support. So there's some features coming.
And that's my high-level overview of plans for my classes, modules, and controls. Stay tuned.