I am using appsmith for the app, with a pgsql db. Then n8n to query pgsql with its JSON functions and finally sending it to apitemplate.io to generate a PDF from the JSON and a template. The PDF then goes into nextcloud. With apitemplate you get 50 executions a month for free, which is enough for my use case. Hope this helps. (The use case is an equipment maintenance tool for the SCBAs of our fire brigade, where I need reporting for proving that maintenance was carried out)
Try Threema… Open source, Swiss based, audited. As you and your data are not the product of this company, it costs 5 bucks. Less than a Starbucks coffee, but I still have a hard time convincing my peers to switch. (Not affiliated with Threema, just a fan)
I use restic with resticprofiles (one config file), notifications via (self hosted) ntfy.sh and wasabi as backend. Been very happy, runs reliably and has all the features of a modern backup solution, especially like the option to mount backups as if it were a filesystem with snapshots as folders, makes finding that one file easy without having to recover)
In Chemistry (where it originated) it is still called NMR. There is no image produced, but a spectrum (graph).
I am using Autosync to sync Obsidian between my mobile, a laptop and a tablet with the central point being Nextcloud. Running without any problems for ca. 3 months.
I do not know Airtable too well, but n8n might have a connector for it. Then you could use the rest. good luck!