Kind of an icky area here, with no real perfect way to handle it.
US 5 and CT 15 have the point where US 5 splits off centered where the ramps enter/exit rather than on Main Street, seemingly trying to capture East River Drive even though only one direction of US 5 would use it.
Exactly. Treating this as a "misbehaving parclo" and cutting across the diagonal of the (NB ramps & Main / E River & SB ramps) couplet, between where the NB & SB alignments split at the ramp gores, to where they rejoin at
SilLn.
Neither US 5 nor CT 15 has a point at CT 2,
In this case, the ramp leaves the mainline along with the Main St / US5 N ramp, so I opted to go "1 point per interchange" and fold it into the 5/15 split point.
and CT 2's 4A point is located a little south of US 5/CT 15.
This was informed by the odd, onramps-only layout, connecting here.