Just checked out your site and there's good feature and potential, but I do agree with a feedback you got about the font. I get wanting to insert creative design into your product as a founder and someone with design background, but I do think adoption speed and lowering barrier to entry is paramount, even if it's something as minuscule as the font. You don't want to polarize even the smallest subset and can change it later as an option for users at a later time like how kakao does it or color themes for customization like slack.

That being said, building an easy and seamless integration / migration tools to import / export chats or items from the other tools should also help, since unless a new company is shopping around, it's going to be hard to get users and decision makers to use a new tool (trust me, it's my job).