Good question @Akhilesh. I think the best version of this I’ve seen is how Superhuman handled it. Have you read the article on First Round Review?
I would recommend making any beta about finding PM Fit. It might be for a feature or for your product. I think one mistake we made was assuming we didn’t have time and rushing this. TAKE YOUR TIME. If you rush now, it will cost you more time later. Keep iterating and keep working with early customers until they are fans and are raving about the product.
One thing we’ve been helping customers with recently is building in “continuous feedback” into their products. We spend so much time on quantitative analysis that we’ve really neglected getting high quality qualitative feedback from users to learn why, and to hear in their own words what they expect. I wrote more about how and why we need a new model for user feedback in the age of product-led.