My PR (on a pancake flat course) came 7 days after doing a hard 100k ride followed by a 20k tempo transition run. Then an easy 4 hour ride the following day.
My only AG IM win came a week after a 70.3, where I absolutely blew up and walk jogged the last 5k of the run. Admittedly, the walk jogging made me question my decision to still race the IM.
It’s not crazy at all, but I do think you need to understand how your body responds to varying taper lengths. I’ve got 25 years in me (43 y/o now) and it took me (and coaches) about 18 years to realize I perform best off of an extremely short taper for long events. If I was you, I’d look back at prior training data and see if you can suss out where your best performances have occurred in relation to the taper you did. If your prior tapers involve some sort of hard longer effort a week out, then let it rip.