Just revisiting this - fairly risky to drain the coolant with it at normal operating temperature and even if that was done, it would be well below operating temperature with the new cold coolant just added and would take longer than 10 minutes to get back up to operating temperature.

I have done two drain-fills on my 2017 Sport.   The fact that the new spec Ford coolant is compatible with the old spec there's no issue with not purging all the old coolant and I didn't purge the system on each occasion - the first time it the fluid in the reservoir didn't look anything like the new color, and with the second drain-fill its closer to the new color.   Maybe next time I'll purge it with distilled water before refilling.

Unfortunately in California we only have 91 octane. I have been running it since new. I think for the ST premium is the only fuel anybody should use.  My owner's manual says the vehicle is designed to run on 10 percent ethanol max. Mine is a 2024 so I cannot imagine any Edges made before mine are designed to exceed that limit. 

I stated concentrated, ie; non-diluted, because when you flush the system as described, you will be left with water still in your system.  By using the concentrate, you will be close to a 50 / 50 mix.   BTW, the concentrate is cheaper than the 50/50 mix from the supply store and you are paying for water. As 1004ron said, I also buy the concentrate and dilute on my own

Not sure who that comment was directed at?   I always buy the concentrate and mix it 50/50 and the product details state clearly not to go higher than 60/40.   My comment was to drain/fill a few times with distilled water and that way you would have removed about all of the old coolant mix, then go back with say a 60/40 mix knowing that the engine still contains some straight distilled water.   I use a vacuum fill kit similar to this. 

Not sure why you recommend pure antifreeze?  Pure ethylene glycol freezes at 10f.  The normal 50:50 mixture freezes at -35f.

One could also use a system like the following to flush out the entire system and then fill with concentrated ( non-diluted ie; 50/50 ) anti-freeze   https://www.amazon.com/dp/B0002SRH5G/?coliid=IBXVQ52CJGVOB&colid=1VY88PYQ3KPE1&psc=1&ref_=list_c_wl_lv_ov_lig_dp_it  

Ya but up here it’s a Ford Titanium Eh! lol  

"Must have been RockAuto." - That doesn't sound like a confident response to me.   Reliable code reading is the best starting point.   .

The only way to get only the new coolant in the system is to do a few drain-fills with distilled water and then the final fill with a higher concentration of the new coolant expecting some distilled water to remain in the engine.