That was our experience in the past as well, but according to a lot of people now, posting more might actually cause you to grow less because of new changes in the algorithm.
There was a time period where I posted 24 times in a day on an account; 10 times a day on another related account. They grew alot & reached many accounts. But those results were conflated with follow/unfollow.
I stopped F/U on those accounts, and the accounts continued to grow.
Then I shifted my strategy to abandon F/U completely.
I started fresh with a set of twin accounts, F/U only until around 2000 followers each. Each account posted 6 times a day.
The accounts steady climbed then took off.
However, the interesting dynamic, they took off at different times at different rates.
The first account, the "little brother," took off and skyrocketed for a while, surpassing the big brother.
The big brother steady climbed, then completely outdid the little brother.
Both accounts are above 100k now, this was tested over 7 months.
Seeing success in just posting that amount alone, I brought the posting test (6x a day) over to my original accounts posting 24x & 10x a day respectively, this time with fresher/quality content.
Both accounts took off in a similar manner, outpacing the days I used F/U.
Lastly, I have an account that took off just posting 6x a day (no likes, follows, unfollows... to this day still follows 0 people). When i burned through the content, I posted manually between 1-3x a day. The account skyrocketed at a faster rate than when it was automated to post 6x a day. Minded I optimized what worked into those 1-3 posts a day.
All these points to emphasize that each account is different. What I have noticed consistently among the accounts, momentum carries each account so long as the account consistently posts. This is the only definitive thing I can find regarding the effects of posting frequency (thought expanded a bit below).
If the account has momentum in growth by a high posting frequency, reducing the frequency doesn't seem to hurt the accounts growth (i've seen quite the contrary). With that said, if the account has no momentum while posting at a high frequency, reducing the frequency to what works best (by the engagement numbers) for the account will give momentum & reach.
These are rough observations I spewed out from my notes, testing, & results.
The answer I assume you are looking for lies in the account momentum- notice how it grows, reach will take care of itself as depicted in the thread. You don't have to prioritize engagement over reach or vice versa.