Cubase already does that if the plugin developer took the necessary steps to make the VST2 and VST3 versions compatible. Sadly, several developers don’t do that and it seems that Spectrasonics belongs to them (i remember another thread with a similar problem with Omnisphere)
Firstly, Keyscape is already available as VST3, but also as VST2, because some Hosts don’t support VST3 (or not fully/unstable).
Why? Imho because Steinberg failed to convince that VST3 offered any real benefits for plugin/hist developers compared to the complexity of porting to it, and the cost of that.
A lot of developers don’t like VST3 because it is quite over engineered and complex, documentation was sparse for a long time, and it lacked features compared to VST2, especially with regards to MIDI processing, and from what I’ve seen on developer forums, communication wasn’t always helpful or constructive, more like “our way or the highway”…
Only when JUCE started offering support for VST3 and Steinberg resorted to legal measures (stopped issuing VST2 license) and brute force (not supporting VST2 on Apple Silicon) adoption rates for VST3 started to climb.
Just my 2c…
You say it’s up to the plugin developer? What is your source for this statement please? It seems to me that the plugin developer would have no mechanism because Cubase 12 Mac Apple Silicon will never open their plugin. It’s a function that would need to occur in the host, to see the VST2 called for in the project and communicate with the VST3 plugin instead?
Then maybe the VST3 plugin needs to confirm that it can handle being substituted for the VST2 version?
Any docs on this I can forward to Spectrasonics please?
Due to this issue I’ve had failed continuity of VST2 to VST3 plugins with Wallander NotePerformer, EastWest Spaces II. and XLN Audio.
At least in the latter case the developer now understands the issue and is addressing it …
The way a DAW project with a lot of plugins loaded works is that inside of the project file, each plugin is stored with a unique numerical ID, which allows you to transfer a project between different computers and operating systems. When loading one of our VST3 plugins in macOS versus loading it in Windows, the ID’s that identified our products were different. That’s why the projects failed to transfer between Windows and macOS: from the point of view of the DAW, our plugins on Windows were entirely different products than our products on macOS. More investigation revealed that the reason for the ID’s differing was that we had built our products with very subtly different build settings, a certain preprocessor macro was set differently on the two platforms.
Steinberg have been a big part of the problem with changing licensing rules and requirement to give up VST2 commercial licenses for a commercial VST3.
And giving out GPL license that conflicting the GPL rules. Let’s hope that VST* dies and we are building plugins with some real standard that can be used on open system and commercial systems without interfering from third-parties.