Without capacity improvements on the Wirral lines where would the Chester trains terminate? Birkenhead North, by memory alone, is perhaps the 'best' candidate.
You could terminate at Hooton, with a few tweaks.
The old P1 (now un-numbered) is still in place, complete with canopy.
It was at one time the Up Fast and the main platform.
It was retained to reverse freight trains for the Helsby line, while Merseyrail took over the Slows which are 3rd rail fitted.
Currently it is just used to reach the footbridge/lift which leads to all the EMU platforms, plus some bike storage.
Rock Ferry is the next option, and used to be the main interchange station for Merseyrail before it was extended southwards.
But I think the platforms would need reconstruction after decades of disuse - trees growing out of the track etc, despite the colour light signalling being still there.
Birkenhead Central has a sort of bay platform that is used to park a spare EMU in the off-peak, but it's too short really.
The layout is very poor there too (used to lead to the old EMU shed).
But Hooton is not a bad option.
It would connect into the 6tph northwards into Liverpool.
Big cheap (council) car park too - £1 a day.
Rock Ferry would interfere with Merseyrail more with the dense service north of Hooton.
Birkenhead Central seems impractical.
Presumably travelling round the loop on diesel would be out.