In principle, BUD is a mid-sized airport where I have never waited more than 10min at Schengen exit / entrance checks (they have automated gates if you have a Schengen passport) and walks are not too long. On the same ticket, I'd be comfortable with a 1.15h transfer. On two separate tickets, it's not so much the airport layout that is the determining factor, but your tolerance for risk. Any inbound flight can be delayed...

Note specifically for arrivals on LX: For mysterious reasons, although ZRH is also Schengen, passengers arriving on LX are always bused directly to baggage claim (as opposed to being let out into the concourse, as is the case for LH/OS). This means you absolutely have to go landside and then re-clear security upstairs. That makes 1:15h on separate tickets very risky.