Indexing a PBN network of sites
PBN networks are a group of sites under a single management, which are created to help promote one (or several) main sites - for example, an online store.
Obviously, in order to influence the rating of the main recipient site, the donor sites of the PBN network must themselves be something: at a minimum, pages with links to the main site must be indexed.
How to index PBN network sites
Since PBN network sites are created as auxiliary ones, then most often:
*filled with average quality content, or even outright plagiarism and rewriting;
*created on templates, without a unique design;
*have a limited budget for promotion.
then the indexing of PBN sites in Google is lower than expected. And, accordingly, in such a situation, the whole idea with PBN collapses.

Even worse, already indexed pages fall out of the index, because Google considers them irrelevant for some reason.
A news site that is part of a PBN network with all the corresponding problems contacted us with this situation.
As we can see, filling the site with new pages-articles does not improve its visibility and influence: the total number of pages increases, but the number of indexed ones does not.
That is, the work on filling the site is done in vain, the site does not fulfill its function.
What we did
We took a list of unindexed pages from Google Search Console and analyzed it, sorting them by reasons for non-indexing, highlighting a group of potentially promising pages.
Based on the number of links, we chose the Grey Ninja tariff, which allows you to process up to 10,000 links (for 5 projects, which is just right in the case of several sites in the PBN network).

Results
Google Search Console displays data with a significant time lag, so we did not see the result right away - but, as it turned out, it first appeared on the same day: the number of indexed pages increased by 2000+, and then by a little more, i.e. - about 90% of the pages sent to 2index.ninja successfully passed indexing!

We are seeing a sharply increased number of impressions of our site - but, naturally, the appearance of site pages in the index does not mean its immediate appearance in the top 10 positions, which brings clicks, but, firstly, the goal was indexing in the first place, as the meaning of the PBN network's existence, and secondly, this is already the "beginning of a good friendship" of the site with the Google index.