How do you approach win back timing?

I’ve been working on a win back flow recently and built it around time since last purchase rather than sending the same message repeatedly.

The first email goes out at 75 days and focuses on new arrivals and brand updates.

At 90 days the messaging shifts to a stronger re engagement offer.

At 105 days there’s a final email before the customer is treated as inactive.

Curious how others here approach win back timing. Do you use fixed windows like this or change them depending on the typical purchase cycle of the brand?