• I'd love to be able to see my turtles on JourneyMap.
• Although turtles seems to be more akin to special furnaces & redstone devices, Turtles move like mobs. It, therefore, seems reasonable that they could be visible on JourneyMap and similar mods.
• Indeed, I find sometimes find myself looking for my turtles on my maps!
• This option would be very helpful for observing the status of a program that makes the turtle cover a lot of ground. It would also be nice to be reminded (or simply informed) where my turtle is at without the use of the /computercraft commands.
• Someone on JM's Discord suggested this same idea a couple months ago, and one of the mods/devs said that this feature would probably come from the CC end of things.

I believe CC typically shies away from addings other mod APIs to the build process, even as soft-dependencies, unless absolutely necessary. I could imagine the behaviour for a JourneyMap integration would become increasingly complex (for example, how do you manage who sees which turtles? How would this work in multiplayer?) - and that it may be better suited for an external peripheral mod that bridges the two mods together.

I would consider this a "Nice to have", but the other two comments (above and below this one) have said pretty much everything else I have to say currently.

I'm going to tag this as "wontfix" for now. I want to think about this a bit more. As Lem says, there's a lot of design decisions here, and I feel this could spiral into a lot of work for a pretty niche feature.

I wonder if a more useful feature would be a separate JourneyMap mod which can just highlight user-configured list of block entities? It's a little cheaty (would could abuse it as a limited x-ray mod), but would be more generic than something CC-specific.