Something happened and I need to resubmit A LOT of sitemaps across a lot of domains.
Is there any way I can submit all sitemaps/all errorful sitemaps per domain even? It would make things easier for me.
You could create a sitemapindex for each domain that lists all sitemaps for that domain:
This will prevent you from having to submit multiple sitemaps for each domain, at least. It also serves as a workaround for the 50,000 page limit for sitemaps, if you ever need to submit more 50,000 pages. (Each sitemap in the sitemap index can have up to 50,000 entries.)