Starting from Q6L3 and going towards IP4, I see these BPMs for beam#1:

6468.9288 BPM.6L3.B1 (last BPM when dumping on TCP)

6512.1628 BPMWE.5L3.B1 6539.7078

BPMW.5L3.B1 6614.8358

BPMWE.4L3.B1 6642.3808

BPMW.4L3.B1 6687.3458

BPMW.4R3.B1 6714.8908

BPMWE.4R3.B1

So going to LSS3R would add another 6 BPMs (2 more BPM front-ends) ..