while i do not believe you have any obligation to license it under an open-source license, i think people who use it under a proprietary license are being foolish. a cas is an essential tool for day-to-day work, and becoming dependent on a proprietary software vendor for that usually ends badly
so in a sense that's a 'sage feature i'd like to see'
I feel similarly. While I myself might gamble on learning a tool like this, I'd be reluctant to recommend it to students unless I was very confident that it would always be there when they reached for it. Source-available does scratch that itch more or less, but it creates some reluctance.
so in a sense that's a 'sage feature i'd like to see'