“Yes but” is now a part of my toolkit to help me authentically unpack all the justifications that come to mind & convert them into learning.
I’ve lead B2B SaaS revenue efforts a number of times. You correctly identified all the things that are hard and how customer size is a major factor in choosing what to build and how to sell.
My general recommendation for a tool like yours is to sell to the professional who would use it in a “b2b2c” format like Slack.
First win the champion, then the market they live in.
Excited to see what you choose next!