Proceeding as planned, I wrote 170 lines of code to make debug-me have separate threads for the user and developer sides, which send one-another updates to the activity chain, and check them for validity. This was fun to implement! And it's lacking only signing to be a full implementation of the debug-me proof chain.
Then I added a network latency simulation to it and tried different latencies up to the latency I measure on my satellite internet link (800 ms or so)
That helped me find two bugs, where it was not handling echo simulation correctly. Something is still not handled quite right, because when I put a network latency delay before sending output from the user side to the developer side, it causes some developer input to get rejected. So I'm for now only inserting latency when the developer is sending input to the user side. Good enough for proof-of-concept.
Result is that, even with a high latency, it feels "natural" to type commands into debug-me. The echo emulation works, so it accepts typeahead.
Using backspace to delete several letters in a row feels "wrong"; the synchronousness requirements prevent that working when latency is high. Same problem for moving around with the arrow keys. Down around 200 ms latency, these problems are not apparent, unless you mash down the backspace or arrow key.
How about using an editor? It seemed reasonably non-annoying at 200 ms latency, although here I do tend to mash down arrow keys and then it moves too fast for debug-me to keep up, and so the cursor movement stalls.
At higher latencies, using an editor was pretty annoying. Where I might normally press the down arrow key N distinct times to get to the line I wanted, that doesn't work in debug-me at 800 ms latency. Of course, over such a slow connection, using an editor is the last thing you want to do anyway, and vi key combos like 9j start to become necessary (and work in debug-me).
Based on these experiements, the synchronousness requirements are not as utterly annoying as I'd feared, especially at typical latencies.
And, it seems worth making debug-me detect when several keys are pressed close together, and send a single packet over the network combining those. That should make it behave better when mashing down a key.
Today's work was sponsored by Jake Vosloo on Patreon