I think you are going to have trouble with this pricing. Limiting the different view types to only the paid level I think will cause a significant blocker for most people. I believe there are other self-hosted options without this limitation (seatable), and much more powerful (non-self hosted options) with much more generous free tiers in terms of functionality.
Personally, I'd keep most of the enterprise-ish integrations in the paid level. So, then someone can leverage the full functionality of the app, but would have to either develop a custom integration via the API, or opt for the paid level to avoid the cost of development. In my experience, you are likely to get most businesses to pay if they really need self-hosting.
Without supporting the views, I think it will be hard to get people in the door using it for smaller, personal needs, before deciding to adopt it more broadly.
Knack is a rapid application development tool that has the underpinnings of spreadsheet like data display but allows to build various applications and integrate authentication, workflow functionality, and actions on events. Think of it as an evolution from MS Access, Hypercard, Filemaker but web oriented. The term that's being thrown around is "No Code". We use Knack extensively and while it has its quirks, it solves spreadsheet hell and enforces workflow when you have multiple users working the same data. Technical startup knowledge is minimal which is why these tools are becoming popular. Amazon has just recently released their own and I expect there will be more in the future.
To get back to OP's original question, it looks as if the developers of Seafile are building their own version called Seatable. My first glance is that it is written in Python and is open source with the exception of one proprietary module. I have yet to put together a Docker image and kick the tires, but look forward to seeing what comes of it.