Originally Posted by
YuropFlyer
On the other hand, since OP arrives clean in E Gates, he could try (no guarantees!) the FCL in E, especially if his BP has "LX9001 First Class" on it. (Not sure what gets printed in SIN in such case of a codeshare booking) - if that doesn't work, it's a good chance they'll just direct-transfer him from the FCL entrance over to the SEN/C side on the same level, so not much time lost that way. He could always play the "newbie" card

And I'd not rule it out that he'll actually be let into the FCL, either due to mistake or due to staff being generous.
Chances are probably more than 90 percent that he will be rejected, as he does not fly long-haul F on LX metal. One can always try, but staff at the FCLs in ZRH is rarely "generous".