Hi @techinnyc1,
We don’t know any effects on the SEO on your side because of blocking archive.org. And yes, the plugin only blocks the archive.org crawlers by adding the following lines to the robots.txt file of your site:
User-agent: ia_archiver
Disallow: /
User-agent: archive.org_bot
Disallow: /
User-agent: ia_archiver-web.archive.org
Disallow: /
You can check this by navigating to the robots.txt in the root of the domain.
Please keep in mind these two paragraphs of the plugin description:
If you activate the plugin it will add some lines to the robots.txt file to tell the Archive.org bots not to crawl and index your page. This means that they won’t store a backup of your site and you won’t be able to browse the different versions of the website through time.
Please keep in mind that if you activate this plugin and your site is deleted from the archive.org index, you can’t undo this. If you remove the plugin and the block of the archive.org bot, they’ll start again crawling and indexing the website from that moment, but all the older information is lost. Be carefull and think if this is what you want to do!. If you mess it nobody will not be able to help you (neither we or archive.org).
Hope this helps.
Best regards from Spain.