I like to go to larger stages where I can mitigate the pressure that lasers create (Skyworld, Ps2, dreamland, lylat, even skyloft, smashville, and battle field). We don't have anything like peach's full hop Float or rob's side-b to get through laser camping, so I like to try to play the neutral like I would as fox, a lot of full hops and platform movement mixed with dash-dancing and attempted powershields. Powershield> AGT is a really really good option to close distance and gain some control of the stage back, and it isn't too difficult especially at larger distances. Another thing to look at is lasers scale down to <1% really fast now, so you'll have a lot more time to try to work your way through them. IIRC if he shoots them at the highest distance you can just run under them, and if he drops them lower you can approach with SH>anything to gain some more space, so a lot of the burden in the neutral in on us to recognize what he is doing and react. Be careful to not do anything to risky against him because if the falcos are good at shine OoS nothing is really safe. Shffl alot of nairs around because is any of them hit the juggle is free. If you know you're going to get shined, DI HARD left or right, with good timing at higher percents it will cause him to drop the combo, and force him to just try to keep the pressure through lasering where you're going to land. still a bad situation but you still have your stock.
I would avoid small stage/blatzones but it depends on your play and the falcos. If you're decent at mitigating the control lasers bring/ the falco doesn't like to spam lasers, FD is a great stage. He does get better combos on you as theres no platforms but you can just juggle him zero to death. Wario Ware puts you guys really close and works as a good stage if the falco prefers lasers as he doesn't have as much room. just be wary because the small blastzones hurt you a lot more, he can end combos early with shine>bair and still just take the stock.
Larger blastzones give you more opportunities to recover, and is falco is recovering at max distance the gimp won't be hard. IF falco has to drop even to/below the ledge, just grab it: it covers side-b sweet spot, and then you have all the time in the world to ledge drop bair him out of up-b. When he recovers high its a bit harder, early side-bs have to be dealt with on reaction, but you can grab/smash him on landing most of the time. If he up-bs from above the ledge I like to just turn around and jump, if he goes high you can land and chase him down, if he goes right at you you can nair/uair/bair, if he goes for the ledge you can fall and hit him with a well timed bair. Try to recover high (side-b early, double jump >horizontal up-b early aiming for platforms is what I like to go for) so you don't have to deal with lasers taking jumps or side-b, and the burden to sweetspot while he shffls dairs isn't as large.
Don't let him go to Yoshis unless you're confident that you're just going to outplay the falco anyway.
His reflector is lagless so be wary about that as well, if he is playing super campy he can just reflect our projectiles and then begin lasering immediately after.
Its slightly in Falco favor, I think it ranges from 60/40 him to 55/45 us based on stages and the styles of the falco and the diddy.
Just take him to skyworld and make him cry.
Not super good at executing the matchup myself, but once falco stops playing campy it just turns into a bloodbath and it boils down to who has better hit-confirms and stock-confirms.