With Trump speaking at the LNC, is there anything he could say to convince big Ls to give him their support?

He can't really point to the past. His Presidency is sorta known for spending $4 trillion on COVID and exacerbating supply chain disruptions, both of which contributed to current inflation. He can't really point to his future. He habitually lies about everything, so there's no reason to believe any promises for the future that would be a break with that. He can't point to being better than his major competition. Big Ls have already inherently rejected that false dichotomy by virtue of being big Ls, so it doesn't really matter whether he can make the case that he's better than Biden with that being enough on it's own.

There's only one major thing I could think of that he could try to get some meaningful bit of that audience to consider him. And that's picking a great VP candidate on the off chance that he doesn't, for either legal or health reasons, serve a full second term. Nobody near the top of the list in the betting markets fit that bill, I'm just thinking out loud about what could possibly matter.