I have been using Instant Indexing API for a while now, but that allows me just to submit pages for Indexing. Whether it gets indexed or not isn't possible to know unless you specifically search for issues in the Search Console.

CrawlWP solved this problem. I didn't even know that 48 out of 1877 of my pages weren't indexed in Google Search Console. Sent a packeted indexing request, and now they are in search results. Totally a lifesaver.