Yes it is.
Tiels poop approx every 15 mins or so. After his first poop, time it, so the next time is ready for him to go to the loo take him straight to his cage, give a simple comand & wait for him to poo. Keep doing this until he gets the idea to go to his cage when he needs to go to the loo. Make sure his cage is open so he can go in their when needed & if he's clipped & unable to access the cage without your help, never leave it too long or he will poo where ever he can if he's busting to go.

Alternatively you can make a simple small stand in the lounge with newspaper at the bottom & train him to potty their.

Can anyone offer similar advice for a Sun Conure?

From what I have read, it is pretty much the same. I have noticed Tango (a PFC) goes about every 20 minutes. I haven't tried really training her yet, as she is clipped and cannot fly to her cage. I have heard that caution needs to be exercised as a bird taught to 'go potty' at one location may only go there...and if they are confined somewhere else, well obvious problems could occur. I have noticed that Tango often will hold it until she is on her playgym (sometimes in the evening for 30 minutes or more) and I do make sure to tell her to "go potty" and praise her afterward. I'd be interested if anyone has successfully gotten their conure trained and has any tips as well.

Good luck.
Tara &Tango
"Use the talents you possess - for the woods would be a very silent place if no birds sang except for the best." ~Henry Van Dyke

Yes it is the same for all birds. You just need to work out how often they go to the loo.

I don't have any problem with my eclectus & potty training. He's been taught to to got o the loo in his cage, on his playgym or on any stand. He's also clipped & clipped parrots become excellent climbers so they are still able to get from place to place as long as you provide branches to climb & get where they want to.