Well, yes. But the blog is an English blog and plural is Juliuses. The rules of grammar apply from the language, not from the word. Sometimes the language inherits the rules from the language of the word. But that's an exception.

Well now we are choosing to inherit a newly contextualised word it's appropriate to discuss what grammar we should take with it

Just ask Julius, then....

Except that the blog is also in French. https://ploum.net/2024-12-23-julius-fr.html

The author is running a poll to establish the plural: https://mamot.fr/@ploum/113704470821790664

But in Latin Julius starts with an I. (with apologies to The Last Crusade)

That assumes Julius is a second declension noun. If it were a third declension noun it would indeed be Juliuses.

In the subject, but e.g. 'Surely you're joking, Juli?' or 'I feel surrounded by Julios.' My Latin is pretty rusty, though.

As we're a tech site, the plural is clearly Juliuxen.