6 month old nap schedule

So far we’ve just done “awake windows” with my now 6 mo old. Right now he’s on a 90 minute awake window , meaning after he’s been awake for 90 minutes is when his next nap starts. Typically then there is a longer stretch before we start bedtime routine at 7. On a good night he’s asleep by 7;45, some nights it’s more like 8:30 🤷‍♀️. In the mornings he wakes between 7-8.

It’s still working well for us, but I feel like we’ll be ready to transition to a more time/ clock based schedule soon (ie nap at 9,12 & 3 or something). My question is for parents on a clock based nap schedule. If they take a particularly long or short nap, do you adjust the time of the next or just stick to the schedule. My LOs naps are typically an hour & 1/2, but like this morning he woke up after 30 minutes. I feel like he’d be so tired for his next nap or the other day he slept for 3 hours 😳....