Hum.... Can you tell me what you're using? Just to give me some ideas.
Oh, now I got your meaning. There is a feature to export your data. Someone on Reddit said they couldn't export "thousands of notes", but the feature is there. The docs say it. And I used it, but I don't use another app, and don't have thousands of notes yet. It's something to take a look.
I can't configure everything yet, but my Vagrantfile can install and activate most of the dependecies on a Fedora Box from Bento (the Hashicorp, developer of Vagrant, builds those optimized system images). Activating Redis with RedisBloom plugin from boot is prooving tricky. After setting the dependencies, I need to configure Ansible and then export the node settings to be used in the app. It'll take me some time. I'll let you know.
Their protocol source is available on GitHub. And there's no need to copy the data file between devices, the sync works on your own node (if you can build the setup), on the same lan and on encrypted cloud.
I believe I'm the noob here, but is it that weird? I mean, in this scenario you're no longer using Anytype, is it really reasonable to expect that all the relations and links you created using it to be transferable to another app? It seems to me like a lot of work to make two different solutions talk to each other so well.What if the other app has a resource you don't want? Or you have a new resource they don't have yet?