Results! - The G5-G6 Challenge - An actual comparison

Yes. For a graphical picture of what is happening see this post:

I superimposed recorded values from SugarMate over the 3-hour delayed values reported to Apple Health from the Dexcom app. The adjustment is consistent with your two sets of numbers [I editted the stuff below to align the numbers and remove the spurious double space in @BillKast’s original post.
I also added emphasis in italics.
]:

What I don’t know yet is whether the adjustment happens in the transmitter or the receiver. Logically it would be the receiver; Dexcom delays an update to Apple Health for three hours, presumably so that it can let that adjustment pan out. The transmitter retains 3 hours of readings, so if you are about to rewrite history probably better not do it for three hours.