That is what @RR503 is referring to when he says Force and Lock. Also described in my post above. It works at Church Ave because the switch in question moves all the time anyway.
Going back to the DGTs though, I noticed an interesting behavior at Roosevelt Ave with the ST (Station Timers) and DGTs there during a GO. It is as follows
enters on the express track, switch is set to normal, no timers active. Home signal is at stop, no route set
then punches for the local and departs, switching to the local track at the prescribed speed. During this time an pulls up short of the station on ST
enters on ST20s that are displayed on mid station semiautomatics (Red over lunar 20). The switch is still in the diverging position
Instead of clearing to yellow, the lunar 20 becomes just a lunar ball, thus dropping to a DGT at the posted speed (lower than 20)
proceeds to the end of the platform, clearing the DGTs at the slower than posted speed. Home signal is at stop.
punches for the express, switch returns to normal, and the then departs.
Why would this happen if the (e) following was stopped and thus supposedly clear the more restrictive DGT speed? And why are the signals allowed to drop to a more restrictive DGT aspect with a lower speed than the ST in this location?
Similarly, at Forest Hills, if there is a train going into the relay with another one right behind it (stopped), couldnt the follower satisfy the lower DGT speed just byholding outside the station? Would it improve the situation to put in such logic if DGTs are really needed?