I tend to agree with your reliable source, I don’t like dry ice in my ethanol.
My preference is a cryobath (dry ice slurry) with a keg in it, or a chiller up for the task.
My issues with it so far have all been with the effervescence it causes. which makes moving it with vacuum or a gear pump difficult.
I have not seen issues with isomerization upon distillation, some do, others seem to get away with it. @Roguelab has way more distillation under his belt than I, and recommends avoiding it. Charcoal filtering - #18 by Roguelab