ranskis

I have not found anything close from Spain to Asia/Oceania in business class, where do you get such LH/LX deals?

Adding a stopover in ZRH adds 100 EUR to the fare, adds 18 EUR to the ZRH tax and saves 46.5 EUR of CDG taxes, so a next cost of 71.50 EUR, not too bad. Adding a stopover in other places adds 100 EUR + additional tax (35 EUR for FRA for instance).
Note that it seems LH group is now applying some married segments logic also for interline connections (like CDG LH FRA LH HKG stopover CX has availability in P for LH flights, but if the stopover in HKG is replaced by a connection keeping the same LH flights, those might sometimes become available in Z or D only althoguh CX is still available in I class).