I would ask for a further promise, that being portable and a quine remains, specifically without needing to run a binary.
I used TiddlyWiki Classic for a while and returned to this software with TW5 recently. It has one thing almost no other such program has. I work in a large corporation where we work only on company machines and their own provisioned software. Importantly I’m not in IT (like most employees) and I’m therefore very restricted in what I can run on my machine. So I’m personally limited to either TiddlyWiki or OneNote (comes with O365) for personal notes. There is absolutely no way that our CISO would let us connect to Obsidian or run Emacs locally to use Org (just an example on two ends of the usability spectrum). Tiddlyhost is also blocked by our work VPN.
So from a very high level perspective for the corporate worker with a typically restricted device, these are killer features for the freeform setup TW is designed around.
Beyond this basic approach, it is about polish and customising in a certain way. These issues are a common theme on this forum so I’ll be brief. As an end-user I would say briefly
- Editing and viewing should be one and the same (with a read-only option of course for publishing)
- BTC’s MultiColumns already shows the interaction that users expect - highly keyboard driven, flexible and clever with grid sizing
- Ease interaction with and access to templates. See point 1 in Dave Gifford’s description of Tana for an example. This would greatly enhance TW’s capability as a database and make a lot of plugins unnecessary; if done right, it would simultaneously make plugin development easier.
- Expand documentation to include many more examples in the filter/variables for the less technical user like me. An approach like https://tldr.sh would work well. The last is more operational than technical, in going around the web and collecting useful snippets. Better SEO would also be a benefit so search engines can readily pick up these pages.
But these are small things - the key is to not require running a webserver or to run from an executable/binary file. It has to be an HTML. Both of the former would be blocked by a corporate firewall, and TW would cease to be an option in the office.
I want to also say to the community that I’m very glad that virtually no-one assumes nodejs is running in the configuration for their plugins, because I will always be a single file user. I also appreciate that while many of you use it in the workplace and are highly empowered/have your own devices, you still work on in-file revision mechanism and other such things. Your asceticism is a blessing to us ‘protected’ from truly personal computing. 
I have faith you will anyway as TW Classic worked much the same, but I haven’t seen my specific scenario mentioned online since the need for running from thumbdrives has declined. So there it is - not sure how common it is, but I can say that many large businesses function the same way when it comes to cybersecurity and what the average employee is permitted to use.