The capitalization of "Open Source" makes it a proper noun or adjective which means it refers to a specific thing. This is why the Open Source Initiative (OSI) always uses "Open Source". You know they are referring to open source as defined by them. "open source" would be referring to the general concept which depending on interpretation could include shared source.

In my view using the proper vs common version of "open source" places this into a disingenuous attempt to be associated with open source as defined by the OSI.

In my view responding immediately with clear clarification of the degree of the code openness, right under the title of the website, places this into this as something which isn't remotely disingenuous. In my view seeing this as disingenuous is, quit frankly, odd.

It is also goes against the site comment's guideline (as well as general sane rule) of: Assume good faith.

Here's a concrete example of the connotation in action: I wouldn't have clicked thru to the comments or the project's site if the title of this posting was "Source-Available Alternative for Zapier".

I saw "Open Source" and assumed, as I suspect many people did, that it was talking about the Open Source Initiative definition of Open Source. Intended or not, those two words carry a connotation for a lot of people. I'd rather not see that connotation watered-down, either.