Great article @mdubakov.
I am a huge fan of Fibery, and although I know that the work I do isn’t necessarily within the niche that you have identified for Fibery, it is the tool that has come closest to providing what I need (and that’s true even before all the improvements that are apparently on the roadmap).
As you may know, I am somewhat obsessed with the concept of a ‘knowledge network’ (see my post here) so there were many things in what you wrote that resonated a great deal.
What I have come to appreciate is that it is the integration of structured and unstructured data that is a key element of what will make a tool successful/valuable. I do though think the ratio of structured:unstructured will probably vary across domains. In my domain, structured information is more important/critical, and that has meant that, in the past, I have experimented with ‘structured’ tools (like Airtable, Coda, and other less known tools) in the hope that I might find ‘the one’ that fits my need.
I appreciate now that I needed to acknowledge the importance of connecting with unstructured information (even if it might not be that it forms a large fraction of what is required in the ‘knowledge network’ for my domain).
Furthermore, I have previously attempted to leverage UML or SysML in the work I do, but I have found that the barrier to entry is too high to reasonably expect model-based engineering to take widespread hold in an organisation. As @rothnic has pointed out, these tools approach the problem from the opposite direction to Fibery, but I think they are too formal and prescriptive to realistically achieve broad adoption. It would certainly be wonderful if FIbery was able to provide bidirectional data entry/editing - that is to say, changes to the whiteboard reflected in changes to the underlying data and vice versa.
@mdubakov I know that you have recently explicitly stated that you are focussing on the product management niche (and excluding others), but I do wonder whether you could consider broadening a little to encompass product development? I’m aware of dozens of tools that you would be able to strongly compete with if you were able to provide relevant app templates: requirements management, test/issue management, PDM, supplier management etc. (Jama, Spirateam, Helix, OpenBOM and even JIRA 
)
I know that you have previously written about the lack of coherence between strategy and implementation, and I wonder if the niche you are targeting is more focussed on the former rather than the latter. Might your efforts in winning over users of Aha! or ProductBoard end up diluting the strength of your overall vision?
Having said all that, I do appreciate from your recent blog post that you are discovering that customers need a really simple intro to fibery in order for it to be ‘sticky’ and since establishing beachhead is vital, a laser focus on the niche is crucial.
So you should probably just ignore me!