I've been slowly building out a webapp [2] that allows people to design a satellite from scratch, and this book provides a lot of the key technical analyses in a really approachable way. As I build out more of the system trades and analysis modules, I'll definitely be referencing this text to make sure the tools can be utilized from the cubesat perspective.
[1]: https://astrobooks.com/spacemissionengineeringthenewsmadsme-...
The goal is to get to exactly what you describe, with drag and drop tools that then basically give you an export of all your interconnects and performance analyses. As you point out, the reality is that the devil is in the details. For now, Vesper is focused mostly on surfacing the high-level, sanity check interface concerns and performance calculations, but I hope it can still add value at the concept definition -> proposal -> PDR phase of a program.
I also agree wholeheartedly with your other comment that some of the biggest challenges are jumping through the regulatory hoops like FCC licensing and range safety, so maybe once I've got the technical stuff limping along I can take a look at how to incorporate that process somewhat.
Is your roadmap more "Satsearch for broader range of spacecraft mass classes" or "generate initial mission and spacecraft architecture from simple input parameters"?
For example if you add/change a radio transmitter, you can see in real-time how that changes your system mass, power, and link margins, or be alerted if your flight computer doesn't support your radio's data interface.
This (hopefully) lets a spacecraft systems engineer iterate through trades more quickly, track performance and margin evolution over a program lifecycle, or quickly develop a baseline for a given mission class.
Definitely quite a bit of work to go to get there but feel free to create an account and poke around and break things.
A more pertinent point might be that some of the recommendations in here are specific to one particular kit for building CubeSats the authors are responsible for, but for many that will be the appeal...