Hey and congratulations!
I think the 'by the book' way is to keep to waking at the 3h mark, the idea being to get most of the calories in during the day and get a long stretch of sleep at night. That said, I wasn't that strict with mine and would let them go a longer stretch of sleep at least once in the day if it seemed they needed it.
If you want to get to a better schedule you can try gradually moving everything forward by 15 mins every few days - this worked really well for us with DD. But I do think time helps too - some very young LOs just seem to have that late night late wake up thing, and it naturally does move earlier as they get older x