In an ideal world, with sufficient funding, I'd build a short extension from Ellesmere Port to Cheshire Oaks, making that the terminus from Liverpool. Services operated by Northern could also terminate there, after reversal at Ellesmere Port. Given that battery technology has advanced, I doubt the mile or so would need to be electrified.
I know it's unlikely to ever happen for many reasons. Threading even a single line from Ellesmere Port to Cheshire Oaks would be difficult, as ideally, you would want to stay on the west side of the M53. A recent housing development alongside the motorway will, I think, have removed any opportunity to build a line on the west side. To the east of the M53 is industrial land, but whilst the line goes under the motorway just after Ellesmere Port station, any new build line would then need to cross the M53 again to get to Cheshire Oaks, which would be expensive.
Stagecoach used to operate service X8, which stopped at Ellesmere Port station & could be used to connect to Cheshire Oaks. My understanding was that the intention was to have a through ticketing arrangement with Merseyrail, but I don't think that ever happened & the X8 has been withdrawn now.