I've also come around to thinking that the ideal connection would be an underground station at East Lake. There are significant reliability challenges to interlining when we have a network that contains so many at-grade crossings and other potential sources of delay.Probably belongs in the fantasy category but wouldn't it work to having Midtown Rail Line enter a tunnel right after Cedar travel under Pioneers & Soldiers Cemetery the Hi Lake Shopping Center have an underground stop below the Blue Line then day light and stop on east side of Minnehaha? You would probably need to close 27th and tear down the building on that corner to make it work but it's currently boarded up according to Google Street View. Trains could reverse out of the station and head back to West Lake Station.
Plus it would set very well for an extension on to East Lake & to Marshall if the demand was ever there. Of course the downside is no interlining.
From a tunnel, you could then head north again, reconnect with the Midtown corridor, and potentially cross the river to serve either the University of parts of St. Paul. I think the options on either end still require a lot more study, but between West and East Lake, there are relatively few good options and they basically all require grade separation.