Yes, and if you clarify that every time you open the door, you'll go along with those procedures, then that's fine.
But I have a hard time believing any player would be okay with this set of events:
DM: You see a door. You check for the traps on the door by first checking the handle but turning it releases a blast of cold air!
Player: Hey, we didn't say that we did that!
DM: you always do that, though
Player: Yeah, but you obviously railroaded us into that trap.
And the DM did. The DM gave them no chance to re-evaluate their SOP and they got hurt because of the assumption. At that point, it really doesn't matter what you were about to say, the DM already violated your agency.
If you're a fighter in melee against a single enemy, the DM has no right to make your attacks for you.
But there has to be a middle ground between me reading off a checklist at every door, and being asked if I'm sure I want to do it in that order, and the DM railroading me into a trap that automatically goes off.
Especially since there is always something that could be done hurt a character who said the wrong thing. It's just tedium of trying to outsmart the DM, while the DM is actively working to make it as painful as possible.
I don't get what you mean. The point isn't that you purposefully put something in there, the point is that the player was curious and decided to check it out. Whether you put something in there is the icing on the cake but even an empty chasm says that nothing has fallen into it since it was created, which could be useful information. It might even alleviate any fears of an ambush coming from within the chasm.
Maybe you don't remember your own example?
"Here's a point of interest: place those famous 30' chasms in your game and, at the very bottom, put some cool magic items from lost adventurers. Make sure the bottom is out of view from the edge.
Watch as the wizards "win" this challenge by shooting their own foot and missing out on something that could have helped the group."
Your entire point was to punish the players for bypassing the chasm. Shown by the quotes are "win" because ha ha, they didn't think to climb into a chasm they couldn't see the bottom of to get treasure they couldn't see. Man, look how they shot themselves in the foot.
What's the point of specifically setting them up to fail if they don't decide to look in random crevices? Sure, if they decide to I might put something in there, because they went and climbed inside the chasm, but I'm not going to set them up so I can chuckle at them thinking they are succeeding by successfully bypassing the challenges, when the reality is they should have been more clever.
You're assuming the trap has a reasonable time limit. Sure, you could wait for the gas to dissipate but it might either be magical gas that doesn't dissipate or it may take days for it to clear.
The flames could also be magical and continuous. The scythe traps don't need to stop.
Now its a dangerous corridor with plenty of saving throws against damage and debuffs but you don't know how long it will take to bypass it.
Taking things as a general procedure for checklists can easily work at your own disadvantage.
Okay, so first this is exactly the same situation if the party failed to detect the trap, except no one is injured, so we're still good.
So we can wait a few days, that's an option. Maybe we send the Unseen servant up to tie a rope to the swinging blades, the hemp rope is pretty strong, and if we can create a rope path to climb up and over the blades and flames then that would work. Have to worry about the poison gas, but maybe it is thinner at the top. Maybe it can plug the vents the gas is coming out of with wax.
I still don't understand how putting party members in harm's way is somehow superior to the Unseen Servant revealing the danger ahead of time. Also, most traps don't keep going for days, and if they are endless and continuous... then why were they not active when we got to the hallway? Is this a trap that has never once ever been set off? I'm just not understanding how we are in a worse situation than we would have been walking down this hallway of obvious and continuous death.