For whatever reasons the LI is exploring the M8s is beyond me. However if they would clear in the ESA tunnels, it would be really for say Mid day turn such as:
NHV-NYP (MN crew)
Quick turn in station with LIRR crew
NYK-PWS
PWS-ESA(GCT)
GCT-PWS
PWS-NYK.
Quick turn with MN crew
For a PM Peak
NYP-NHV.
The above is just an example drawing a turn out for a member of the forum.
As for something like the above shown equipment turn actually happenin, would probably be subject to equipment availability at the moment.
If the LIRR was "in the bag" I wouldn't be supproised to see M8s heading to KO, Babylon, or Huntington. They fit and got the time to go, guess what, they're going. Like it or not!
For emergency reasons at that NJT/Amtrak DMs would probably be able to come to LI if the need materialized.
The narrow, selfish one track isolationism that has for years ruined the LIRR needs to be flush down the drain.
Like it or not. To increase capacity in Penn requires through service. But the isolationist have derailed that train here before. And not up for further discussion.