Sleep training 6 mo old's naps

My 6 months old's naps are around 2/2/2/2.

Our nighttime routine and night sleep is good. My issue is naps.

Morning wakeup time is around 7:30am and they are usually asleep at around 7pm give or take a few

We just went down to 3 naps, and naps had been 30-40 minutes. We started doing the "crib hour" method to help our baby to connect their sleep cycles. We have been doing this for 8 days now, but now they struggle to stay asleep past the 30 minute mark.

Should we continue to work on this method? Are there certain tips, tricks, ot methods that are recommended? It would be so nice if we could get naps to lengthen. I'd even be happy to return to the 30-40 minute long naps at this point.

Total daytime sleep is lucky to reach 2 hours, and it's been closer to 90 minutes the past couple days. Nighttime sleep is good, feeding and pooping are both good.