Agree with both. With a 4" slab make sure thickness is tightly controlled or thickness variations will create their own control joints... otherwise known as random cracking.
Use an "early entry" saw. with this, should be able to satrt sawcutting within about 2 hours after the completion of the floor finishing operation. Waiting 18 hours or more is too long.
..and you they have to be prepared to work after hours to get on the sawcutting quickly enough...that is a big struggle to get them to do that, and may not be so necessary if it is going to be covered wth carpet or other flexible finshes,,,
It’s no trick to get the answers when you have all the data. The trick is to get the answers when you only have half the data and half that is wrong and you don’t know which half - LORD KELVIN
abusementpark...my spec says "Sawcut joints shall be made to a depth of at least 1/4 of the slab thickness and shall be started as soon as practicable after placement when the saw does not cause raveling of the cut edge. Sawcut joints shall be placed no longer than 8 hours after placement of the concrete and shall be made on the same day as placement."
