Hiya!
I would prefer if a lot of modules would make more use of cheat sheets. This also applies to the way they make maps for campaign modules.
--SNIP--
But does everything need to be predefined? I think they could write these modules more loosely.
I agree 83%.

I like to see a bit more than what I saw in that "blueprint map package" for an actual "adventure module", but I found it nice that they included these level by level sheets with number, description, and a blank space for me to use however I want. I could have written out more in them, or I could have written out a "full adventure write up" and just referenced a page or encounter name (ex: "3. Great hall. -Mud Halls booklet, page 8", for example).
One module I ran that was made for
Swords & Wizardry. I was using the Dominion Rules (free;
http://www.dominionrules.org ) system in my own little "Dominion of Alstigar" (
https://dominions-of-alstigar.obsidianportal.com/ ). Anyway, the module was called
Tomb of the Iron God (I bought it from Frog God Games:
https://froggodgames.com/tomb-iron-god ). In it, it has the more standard layout.
It starts with a 2 pages of 'background info' that sets the stage for the adventure location (more like 1 page... an Introduction and a half-page rumor list to roll on if you want). It then jumps straight into the adventure locations, level by level. Each level has a paragraph on what the level was used for, a random monster chart, and then straight into room location descriptions. The descriptions are short and sweet, but I could have done without the "read aloud text" to some rooms where the text included monsters and stuff that, once killed, pretty much makes that text obsolete. I'd rather have my simple list of 'evocative wording' (e.g., "dusty, dry, rat tracks, twigs/rags along corners, hot-metal smell"), but easily reduced or ignored. The cool thing about this adventure is that right after all that, it has a big blank "box" called "Location # Notes:". This let me fill in what I wanted or make specific notes when the PC's altered the area so that if/when they went back 4 sessions later I would know that they rested up here after a big and bloody battle. I could 'restock' that room with something different that moved in while they were gone, for example. Seeing as I was using a completely different system, I used it for that as well. I printed the adventure out, so had no qualms about writing in it. But I have used sticky-note paper before, when I didn't want to "permanently" write on my print out.
When I write up my own "full" adventures, I use this method. I've actually used this method of "blank boxing" after a location area for a while now. Makes keeping notes or doing campaign session write ups really easy!

I'd love to see 5e adventures done like this. I'd rather have a "paragraph or two" of blank space than a "paragraph or two" of how some monster doesn't like some specific other monster nine rooms down (especially if I read it and realize the PC's already killed said monster!). To me,
that is much more "wasted" than a blank box of space.
^_^
Paul L. Ming