Hey @James_Eades I empathize with what you have written and myself have butted up against many of the limits. At the end of the day you have to realize that while that seems like a huge limitation for the app, and in a sense it is, there is still so much that can be done at the <10k row space. Take a look at the template gallery. People can organize their household, small business, meetings, processes, etc.
You, like many of us in the community here, see the massive potential to use no-code apps to just focus on the ‘building’ of our creative pursuit rather than dealing with the infrastructure (servers, security, etc). However, as we write this in May 2020, if you want to have a massively scalable app (and I know that your 5 employees @ 40 notes a day doesn’t seem 'massively scalable, but in this sense it is) you still have to deal with all that stuff that none of us here want to deal with (servers, security, etc).
I was somewhat early to Coda and dealt with many of these issues, and I can say Coda has been very conscientious and made a huge amount of progress. Things just work better over time as they slipstream improvements into the app. So it is getting better over time, and will continue to do so.
There is a LOT you can do with cross doc to address the limitations, but there’s a high cost in scheming, testing and implementation. I too have built a to-do manager custom for my team and once we hit ~3,000 rows it wasn’t much fun to use any more. I built an archiver:
that stores 30 days of data (for reporting) in the functional app and then every night moves the 31+ data out and the app is again snappy and fun. It was tedious to develop and test the cross-doc, but definitely worth it and made me better at computer science and coda.
So, if you’re creative and patient you can develop work arounds until Coda builds the infrastructure to scale (and probably the accompanying business model) which I am confident they will. Coda has confirmed to me several times that they are interested in allowing Makers to sell/license their docs/apps to third parties which will inherently bring the scaling issues, so it is de facto in the roadmap to eventually address.
My advice would be to work around it for now (it also will make you focus on efficiency and leanness which is a great practice to have anyways) and eventually, when you’re app is nice and polished and ready for the masses, hopefully Coda will be too!