Is SQ check-in possible at LHR with LX?

[MathNerd]

Long story short, is it possible to check-in at LHR for an LX LHR-ZRH flight, with an SQ ZRH-SIN-BLR itinerary immediately following arrival into ZRH?
Ideally, it would be best to get the boarding passes for LHR-ZRH (LX) and ZRH-SIN-BLR (SQ) both at LHR, allowing the stay at ZRH to be entirely inside the transit area.

The LX flight and SQ flights will be on separate itineraries (LX one itinerary and both SQ flights another, single, itinerary).
If it matters, LX LHR-ZRH would be a cash Y ticket, while SQ ZRH-SIN-BLR is an award J redemption.

From what I've read on both the Swiss government website as well as TravelDoc, an itinerary such as this doesn't require a transit visa or anything.

Has anyone here done something similar in Europe? Would love to hear the collective experience of AFF.

 

[MathNerd]

Just an update:

Rang SQ, and as usual, stellar customer service. The consultant mentioned that it's possible to add an LX flight onto the beginning of an SQ ticket, keep the same PNR, and hence keep the whole thing together. Since the SQ flights are award flights, the LX ticket also needs to be an award ticket. No worries, all good, there was plenty of availability (in both Y and J) for SQ to issue tickets on LX (on SQ stock of course).
And then we hit a tiny snag... the SQ ticket was booked using my KF miles, however my KF account is sitting on a big fat zero at the moment. My wife, who is the other pax on this itinerary, has enough miles to make the LX booking. However, you can't add on a flight booked with someone else's miles to an itinerary booked with your own miles. Drat, there goes the plan of keeping everything on the one PNR.
Anyway, so off we went to login to my wife's KF, booked the LX ticket (on SQ stock of course), then called up SQ to "link" the PNRs together (for what it's worth).
Now just to cross our fingers hoping that check-in at LHR goes well.

Question: Of course if LX issues all the BPs for the entire journey, they'll be on LX BP stock. Any way to get (at least the SQ segments) the BPs on SQ stock?