Hi @Brett (glad to see you're still checking in on progress here...8 months later...)
My optimism has raised considerably with recent developments that I can produce an artifact that could attract collaborators in the near term.
Binding has undergone a renaissance which touches every aspect of the system, and has made the API far more accessible for interfacing with other languages. It almost feels like magic.
I think the Big Alien Proposal--kicked off by @IngoHohmann's suggestion that /foo run functions--is about to clean house. It will push the expressivity to new heights, and bring readability and security/coherence to the source. It wipes away the anxiety about writing "correct" source when that "correct" source is hideous to look at, by making the default safe.
I'm getting happier with the naming inside the C interpreter source with things like Flex instead of REBSER or Series and ANY-LIST! instead of ANY-ARRAY!. It might seem like naming isn't a big deal, but I think these changes are integral to having people be able to come up to speed on what's going on when they're reading the implementation.
If there's going to be a "product" from this I will need help (as @bradrn has pointed out). But I've been very reticent to advertise because of anxiety about all the problems I know are there that make me uncomfortable with programs that are as small as print {Hello World}. And when you look at things that are as disruptive as the Big Alien Proposal... my reticence is justified. I couldn't make these changes if even a few users were trying to live stable lives with their code.
(I remember--though can't find proof--that a decade ago it was pointed out that Red/System's PRINT didn't add a newline while Red's did. There was reluctance to change it because "users were depending on the behavior". @earl was in disbelief.)
But my feelings are changing, and I'm definitely seeing the light at the end of the tunnel. So outreach may be coming. And adding to it, using AI gives a big leg up on some tasks--things like Blazor integration--so the rate of progress may pick up substantially.
Anyway--there's more hope now that it can be more than a paper. Check back in a bit. 