I got this one last year, fits nicely on the lower grate of my 23" for smash burgers. Covers 2 burners on my indoor stove.
https://smile.amazon.com/gp/product/B002CMLTXG
I got the locking nuts for mine when they came out. No worries about the gas door leaking anymore! Especially since I like to push the ashes up against it, which in the past caused some leakage.
Yes, with enough time to equilibrate, they get pretty close to each other (within 20F). A little more deviation at higher temps due to more airflow through the top hat.
Learned that lesson on one of my 1st MEATER cooks - ambient temps went haywire, opened the lid and saw the end of the probe was all gunked up with burned on juices/fat.
Not yet, I did use some of the lemon myrtle coconut chili sauce on some duck sliders last night. Yummy.
@Aussie Ora - so, was that a definite YES on the new Makers Mark glass??