I don't know how to tell if we have product market fit or not. My co-founder believes we have product market fit. My co-founder talked to 10 people when he was researching. 5 people showed strong interest and we started developing. We aren't tracking any metrics. KPIs haven't been defined yet. We have had many instances where a single opinion changed the design/requirements.
Some good advice I heard is to find and focus on a KPI that aligns with the sort of use that'd indicate healthy consumption of your product+costs, with a guiding principle of "if people are paying us and using it with a trendline moving the right direction, we're succeeding."
Have you thought about what you'd need to do to get more users/get more eyes? (Presuming you've proven enough traction+lack of churn from existing users that it wouldn't be premature) Similarly, are you talking to users who find value in your product and identifying ways you could provide more value?
I personally see tons of potential avenues for growth given what you've said; but obviously saying this ignorant of much of the reality on the ground so take it with a major grain of salt.