If you arrive in GVA on LX F, I think you have indeed access to the GVA FCL, but if I am not wrong, that's limited to flights NYC GVA, since all other LX flights with F are from/to ZRH.
At least 1.5 years ago, I can tell you that what I was writing above is correct: no F lounge access in GVA when arriving in F in ZRH, several other FT folks were writing about it and I experienced it myself. Perhaps it has changed for the better but I doubt.

From my experience CDG-GVA-ZRH-NBO in First, you have access to the FCL. Travel date: March 2019

But, it was just a separated area at the end of the lounge, but with personal service.

Flying out of ZRH in F is a different story. Have you try to access the FCL in GVA on the reverse itinerary NBO ZRH GVA CDG with NBO ZRH on LX F?

FCL is only date of flight. PVG/PEK-ZRH arrival and ZRH-ARN departure are almost certainly not on the same day.

PVG LX189 and LX1254; BJS LX197 and LX1250 or LX1254. Not on the same day???

Connection to ARN was asked, so I replied accordingly.

Hi,

YES! I was wrong. I flew CDG-ZRH-NBO and then NBO-DAR-ZRH-GVA-CDG

Rebooking of this ticket
 

Due to pandemic of coronavirus, SWISS has introducing waiver policy for rebooking,

The FAQ from SWISS website:

Q: I have a non-rebookable flight booking with a departure date up to April 30. Can I rebook to a later date?

A: Due to the coronavirus, you can once rebook your flight ticket for the same route to a later date up to December 31, 2020, without any rebooking fee. If the original booking class is no longer available, you have to pay the corresponding difference. Please note that this special waiver policy currently cannot be carried out on swiss.com. If you want to rebook, please follow our rebooking and cancellation process (you will find this in the last question).


However, for tickets issued with this companion fare, the fare basis no longer exists. Therefore the ticket can't be reissued with the original price.

For a totally unused ticket, is it possible to rebook the flight segments for the same route and booking class according to the historical fare basis?

Nope. That's the catch about this "free" rebooking. It's even worse in lower classes as LH virtually closed all low booking classes in Economy for example. Quite a poor move imho.