That is a lot of hours for a very small battery. Have you looked at how bright it is when you are a 100 meters away in daylight? That was what I did with my taillights before I decided if I wanted to rely on them.

I was surprised by your capacity rating so I checked, the sheet you linked to lists capacity as 260 mah. The 745 number is milli watt hour.

Energizer lists their 2032 battery at 235 mah, which is only slightly less than the Procell you cite.
https://data.energizer.com/pdfs/cr2032.pdf

I usually run a pair of Ikea low dischage AAA batteries in my Planet Bike Superflash taillights, they are rated at 700 or 900 mah (older ones were 900). I usually recharge them once a week whether they need it or not when on a bike tour, I want them to stay bright. If I needed to replace with disposables, AAA are easily obtainable.

Thanks for the analysis, I will not bother checking out rechargeable 2032 batteries. I go through a lot of those batteries each year and considered checking the rechargeables. I had to replace a 2032 in two devices in the past month, I usually buy 20 about at a time.