Awesome - I'll chuck a couple quid your way for the enhanced edition.
I feel like you should make a decision on how you want to proceed with this project as you seem to be at a sort of crossroads.
1. Do you continue to develop as you are?
2. Do you encourage future development primarily by the community via marketing?
3. Do you want a big publisher to pick up the project and run with it?
4. Do you commit more development time yourselves (not preferred/wanted)?
How do you want to proceed? You can always call on the community to try and help grow the community too, though I think a steam release would be beneficial as it legitimises the game.
Shadows started life as a That Which Sleeps proof of concept if I remember correctly. I don't mean the following to be harsh critique, so apologies in advance if it comes across that way but Shadows still lacks much of the most engaging elements of TWS. TWS was pitched as this dark fantasy, narratively driven, pseudo boardgame with procedural, narrative gameplay. Politics was an optional part of the game, as was military, magic/rituals, relations, trade/economics and the other systems that supposedly worked together to make the game. Now Shadows actually exists, so you've already surpassed TWS in that respect, but my point is that your primary target audience, at least to start with, was those who craved TWS but for obvious reasons were unable to play anything like it.
Shadows has the political systems down and to a degree some of the insidious magic systems, but it does not have meaningful combat (a staple in many games likes this), it does not have any economic gameplay and, crucially in my opinion, it lacks any real narrative drive. I can't emphasize this enough - one of, if not THE main draw of TWS was the ability to 'tell a story'. We wanted to influence the story/ies of the heroes trying to thwart this evil power in fun and engaging ways. We wanted to see Bilbo Fraggins go mad while trying to destroy the ring. Or perhaps our plans fail and against the odds he succeeded. But that was part of the fun to tell and experience those tales. Similar to how Rimworld, or even Dwarf Fortress allows for emergent narrative gameplay. The fun of the game isn't 'winning' - it's about experiencing a unique and interesting story through play. While I think there is a story getting told when I play Shadows, I have to work to find it and sometimes fill in the gaps.
If you want to grow the community quickly, my recommendation would be to make as close a game to TWS as is feasible (or closer in some key respects), to draw in that crowd first and foremost, since it was the root beginnings of Shadows. The community will grow organically too - if you look at the TWS wiki (that still exists, bless), it was all fan made.
There is a market for a TWS-like game - there is an active TWS discord, their YouTube and Kickstarter pages both still get regular comments and there are other games with a similar feel currently in production.
Regardless - thanks for the update as always, have a great Xmas and New Year.