Early Stage Market Feedback

I'm building a pretty niche product, in a space that's not well validated since it's dominated by services firms, not software companies. So its taking a lot of discovery and also a huge amount of market education. This is already a bit of a distraction (but also great to help me think through the use cases) as I've been writing a public wiki in my spare time to explore the concepts and also evangelize what we are doing. The product is a security engineering workflow and risk management tool to help engineers (security and non-security) design and build more securely at the site (greenfield) level, as well as system and product level (brownfield).

As has been stated here many times, getting early stage feedback is invaluable, and its already prompted some minor pivots before I've even released. I have paying customers signed up for the prerelease (which won't ship for another month or so), and 10 practitioners that are providing me feedback on a monthly cadence where I run 1 on 1 calls with them 1 at a time to avoid groupthink and also because some of them are competitors to each other and not friendly. This consumes about 15 hrs/month of my time for planning, running calls and revising the user stories and roadmaps. It also tends to inject delays into the MVP, but its keeping me closer to product market fit.

My question for the group, is how much validation should I be shooting for? How much delay should I tolerate before I ship something that I know is not going to solve the core problem? It seems theres probably a balance here, and my activities are producing a huge amount of value since it keeps me from working on things that arent going to result in a valuable experience, but I also want to avoid perfection as well so I can get this out the door.

How do YOU measure "good enough" before you ship? Especially when you don't need to ship to get feedback. For reference, I started planning the build mid to late 2022, and have been actively building for about 90 days now.