The only thing Jaak has said about a batch 3 is that it is coming sometime in 2026. Note that the first 2 batches were units that were already built/mostly built so that’s why they were able to go out as quickly as they did. Kinotone consists of only two wonderful humans that do everything when it comes to making these devices.
Historically being on this forum is the best way to get notified that there is some sort of batch/pre-order/b-stock sale/thing to buy. I don’t know if they are working on a different system, but I’d not bet on it. You can read up on making sure your notifications are setup properly here. There’s also a known “issue” that if you have a forum window open and active, you won’t get the email notification for Announcements. That’s (from what I understand) just how these forums work and isn’t something that can be adjusted.
Lastly, I’m not a part of Kinotone, but like to consider myself a fanboy of both Jaak and Hannah. So you can take everything I’ve said with several grains of salt.