Asking for Opinions

So~ I recently got deadnamed by a guy who has retired from my company but has since joined another firm as a consultant / advisor. Our firm generally buy services from them, and I am attending an industry event soon and his company is hosting a networking session there. Within the invitation to the networking event, the guy deadnamed me.

I had never personally come out to him because he only had a brief overlap with me when I first started at the company. But I qould say most in my circle of connections probably heard through the vines that I came out (especially since I have come out for a number of years already). Given that fact though, I cannot definitively tell whether he just didn't know, or if he was trying to belittle me in a way, which will be super strange since we are their firm's clients technically so he has nothing to gain really to make me feel *** about his deadnaming. Regardless, I need to make a decision how I should respond, and I have thought of 3 options below:

1. Thank him for the invite and basically come out to him before the event. Depending on how he responds, I will know whether it's deliberate, or if it is an honest mistake. Based on that, I will then react accordingly.

2. Do not directly respond to the invite, but show up at the networking event instead. Ignore him during the event if he doesn't initiate conversation, just like him ignoring the fact I am no longer who I used to be. If he comes over to chat while I am there, just be cordial if he didn't seem to recognize me, or correct him if he deadnames me again.

3. Do not respond to the invite and just don't show up either.

What do you all think about these approaches and which may work best (and why)? Do you have other ideas other than these few options that you see? Let me know, thank you!