Devs, I spent the last 700 hrs skating realistic street style and I gotta be honest; 3-input grabs are so incredibly inconsistent I have yet to be able to add one to a line. I have been trying t...
They are consistent, the game just shows you the most consistent way which is to confirm the nosegrab/tailgrab first and then B/Circle, once you get really used to doing these tricks you can just go straight into the airwalk/tailwalk. If you're mostly a realistic street skater type of player it's common to not be super familiar with the grabs because most street lines just don't give you the airtime you need.
I think what was happening to me was different than just mis-input.
I really got the Airwalk down now but I have to press all 3 at the same time? It's weird.
The issue I was having was near the Vault Tunnel. There's a ramp with a rail on one side of the vault tunnel and I was trying OVER AND OVER to airwalk down the ramp but it kept doing the Christ Air regardless of how accurate my input was for the airwalk.
I had the airwalk down by the time I was trying this. It was almost like the game was acting different once that little down-ramp was in front of me almost like I wouldn't have enough air-time for the grab so it would just do a christ air? But then once I turn around and ramp off a different spot the airwalk would work.
Either something is inherently wrong with down-ramps and 3-button grabs because they become impossible down a down-ramp like the one near the Vault Tunnel. I wanted a line starting with the airwalk and it wouldn't work there so i had to go somewhere else lmao.
I can tell you exactly what's going wrong, it's not a bug.
People will often mistakenly press the grab button while they're pulling the stick down or up for tail or nose grab. If you complete the grab before you've confirmed the board's position, it will just be a normal BS grab and so when you press B, you will do a Christ Air.
The reason they're presented that way is that you have to hold the grab to stay nosegrab/tailgrab, that is a combination you must do. People misinterpret it as a simultaneous action, and that's why they will keep doing Christ Airs. The grab animation will always take priority over the right stick, so you have to follow the game's exact order.
Right stick first, then grab and no-foot. People mistakenly think of nose grabs as a combination of two actions, rather than a chain of inputs. When you get good enough, you can frontload the right stick inputs - like a fighting game - to do combo grabs fast.
So the input requires practice and some patience, but it is 100% consistent with no issues.
Edit, if you're skating vert, you may want to try holding the controller a little differently. Instead of my thumb being used for pushing, I use my index finger to press the face buttons, and for the shoulder buttons I use my middle finger for the bumper and my ring finger for the trigger. That leaves my thumb free to stay on the right stick at all times.