I played an Escape Room for the first time about a month ago.
Some other design "choices" I thought were mistakes from my point of view:
Giving you a hammer before you even see the nail - one of the puzzles awarded a calculator which caused my group to go crazy adding/subtracting/multiplying/dividing numbers based on vague mentions of "putting things together" when the puzzle it was used for wasn't even visible at that point. Comparatively, I found the situation where there was a hole in the wall that you could look through but couldn't see anything of note was clever once one of the other puzzles awarded a scope. Similarly was a key that couldn't be reached but was obtainable once a magnet was discovered.
Not accounting for possible sequence-breaking - one of the puzzles I encountered was literally supposed to be solved by taking a set of letters and solving an anagram on a lockbox with no relation to that lockbox under the argument that "It should be the only letter lockbox left at that point" when you get all the letters. One of our guys "brute forced" a locker based on having 3 out of the 4 numbers and just trying all 10 possible combinations for the last digit, so we ended up "sequence breaking" and when it came to having these letters we had no idea what was supposed to go to what. If a puzzle relies on previous puzzles solved in a certain order, proper means to prevent sequence-breaking should be put in place. One of the initial sequence-breaking prevention mechanisms was that half of area wasn't even accessible initially until a "hidden door" was discovered. That's not practical for a "portable" version of the escape room but there are other mechanisms to stop sequence-breaking.
Too many red-herrings. One of the puzzles involved these objects that were supposed to be viewed a certain way that would make them look like a set of numbers, but one of the objects was different from the others and it had a 4-digit number scribbled on it on the bottom. The room had originally been designed one way but ended up being re-worked with a different set of puzzles after it had been spoiled and perhaps this element was missed or just ignored, but it convinced the whole group including myself that the number was important and that we needed to find how to use the number. We ended up having to get a hint because the entire group was bottlenecked by this one false clue.