For a new site, would you publish more pages or improve the ones Google is already testing?

I'm experimenting with SEO for a new product site and recently crossed the first 500 Google Search impressions.

One thing surprised me: Search Console is already showing a few long-tail queries where existing pages are getting much better positions than the rest of the site.

That leaves me with a decision:

A. Keep publishing new long-tail pages

or

B. Spend more time improving the pages Google is already testing

My current thinking is to prioritize pages already ranking around positions 10–30, improve their content and internal linking, while publishing new pages more slowly.

For makers who've grown a new site through SEO: at this early stage, how do you balance creating new pages versus improving pages that already have impressions?

I'd especially be interested in what signals you use in Search Console to make that decision.