Some recruiters may think that you want your initial to be included. I’ve seen multiple posts talking about purposefully ignoring communication when there are small spelling mistakes in their names. Missing a whole initial may be one of those red flags for some.

In the US, at least, the 99% of spam templates are using just the first name so you get "Hi, George W.! I am impressed with your work at Arbusto Energy, when can we hop on a quick call?"

Instead of an initial, I'd recommend putting an emoji in the first name. (And putting your last name as your full name). I've been able to filter out most "InMail/auto" when they say something along the lines of "Hi {emoji}."

I learned of it here: https://www.glennstovall.com/the-wolf-test/

A Chinese 囧 works great for emoji first names that will avoid emoji filtering on the other side.

I wonder if a Unicode RTL marker would work? (but what if your name is a palindrome)

Or a non-breaking space?

The issue, I think, is with false positives. If I were a recruiter, I'd pay attention to how someone would like to represent themselves, and that would include not altering the data they gave, so, I'd basically copy-paste the info from the First name field, and act like it's natural to call you that.

Of course if you still find satisfying work with good pay, then your system works well. But I'd like better accuracy in, say, an email spam solution.

I add an emoji to the front of my name. 90% of emails I get are clearly bots.

Anyone who thinks there are majority real people behind these emails is a fool.