As a solo founder I have a couple of startups[0] and I built Zigpoll[1] to help with this problem. It lets you embed a non-obtrusive micro-survey / contact us form directly into your website. You can use our javascript API to make it appear based on sign up, time on site, exit intent, etc... it's up to you. You could also email it out to your customers if you prefer.
Also I have to point out there are other competitors in this space you could also use like Drift, Intercom, or even an automated email flow with Calendly for example.