With the new re-inforced sides of the window/door blocks - some of the stated opening sizes need to be updated.
It looks like the some openings were updated: WikiHouse
- 2328 wide = 2400 - (4*18) ← this is correct
https://www.wikihouse.cc/skylark-250/door-m1
- 1164 wide = 1200 - (2*18) ← this is incorrect, it should be 1128