generally you can either run up on them (there's a certain distance where falcos will generally overshoot you whlie firing the lasers ) or preemptively jump over the lasers so that you land and punish the landing lag.
The best advice I can give OP is to look through VODs to see people's setups to punish it (so, you can search for any set where mang0's falco loses, for example).
You can also practice against the tech-spamming 20XX 4.05 cpu by letting it have ledge and just covering the double laser option, it's a little tedious, but it does all of its techniques from the ledge at random so you always have a chance to see it even if you're clearly in a position to punish it (ideally in friendlies your opponent wouldn't make such a poor option choice if you're in a position to punish it).
Oh, also, generally the side platforms are a good spot to be if you know how to quickly fall-through (see: shai dropping if you're dash dancing and isai dropping if you're landing or lasering) to punish. Like, falcos double lasering from ledge tend to land under or near the side plats.