I hope Ernesti gets a chance to meet fellow mecha fanboy Ryuusei Date.
Unfortunately they probably won't have any interactions since Ryuusei is pre-order DLC. Maybe if you wait to recruit him until after you have Ernie, but I did the SRX recruitment fairly early on and the only cross series interactions the team had was mentioning that they were part of Londo Bell in their world and recognizing Uso, confirming that they're from Alphaverse and not OGverse, with no appearances in any cutscenes or such afterwards