Hi Dirrogate! Thanks very much for this feedback; we really appreciate you taking the time to pull this together. Good news: we’re working on all of this 
Tracking issues: two parts here:
- ‘Forgetting’ placement: Quick fix is to disable ‘Follow Match Updates’ on your Proxies:
We are considering setting this to default off, to disable placement changes that you’re seeing. The downside is that your content may match to one piece of data, and then as you continue to scan, you find a much better fit for that content, but not reassess the layout with this option off. We’re working on improving this behavior in general.
The other thing you can check out is disabling scanning at a certain point in your app: namely once the user indicates that they’re done scanning and want the experience to start now. You can do this using via the script posted by Schoen in: Reset MARS . If you put that script on an object in your scene, you can hook into its TogglePaused method through a UnityEvent:
(in this case this is on a UI Button’s ‘click’ event)
- Tracking compared to native: we’re investigating improvements to tracking. MARS is a number of layers up the stack, so is dependent on the tracking we get from the platform itself, and then also from other SDK layers between them and MARS. We also see that native apps seem to be tracking better than what we’re getting in builds. We’re investigating now and hope to have an update on this in the 1.4 update.
Documentation: Updates coming! MARS 1.3, which just came out, includes documentation updates, and we are actively adding additional documentation (and additional tooltips and in-editor help) for Conditions, Actions, etc in upcoming versions (1.3.1 & 1.4).
Examples: Our Content team is always working to advance our example scenes, projects, & learning samples (including simple & focused how-to videos like you mention). We’re currently working on in-editor tutorials, improved discovery for all of the existing advanced examples and use-cases, followed up with simple examples of all basic features.
Errors: Thanks for pointing these out; user-facing errors are always top priority for us to fix when these come up. It’s a little hard to say from your video, but I think the error you see there has been fixed in 1.3. In either case, if you see it again, please send us the stacktrace (the text in the bottom panel of the Console window if you click on one of those errors) and we can really ensure it’s taken care of.
Generally speaking, the use case you describe – Cinematic AR with characters able to navigate and respond to your environment – is definitely a use-case we aim to have solved. The MARS NavMesh package & examples (namely the “Game - Advanced” template) is for precisely this scenario. That template doesn’t go all the way to what you’ve described (the robot character is user controlled, not an auto-navigating agent; and that scene isn’t set up with proxies to react to simple furniture). We very much want to make sure this use case works well, so if you’re open to it, it’d be great to get on a call together, talk through any roadblocks you’re having, and take care of any issues.
Thanks again for taking the time to give us this feedback! We’d love to get it all worked out with you.