Does Vyvanse work better when taken in sync with your natural sleep schedule?

My natural sleep timing has always been 4-6am to early afternoon. For most of my life I fought this with various tricks and supplements to conform to normal sleep times.

When I was forcing a conventional schedule and taking Vyvanse, I noticed it never lasted more than around 3 hours regardless of dose, and the crash afterward was pretty rough.

Lately I've had the flexibility to sleep on my natural schedule, taking Vyvanse after I wake up in the afternoon. The difference is noticeable: it lasts longer, the crash is gone, and it doesn't seem to cause any sleep disturbances the way it used to.

Curious if anyone else has experienced this. Does Vyvanse (or stimulants generally) seem more effective when taken aligned with your actual wake time rather than a forced schedule?