@TYancy, have you ever seen or tried Xpressive ( $19 via Mac App store ) ? I actually bought it on New Years Eve (impressive night huh), to review it's GUI.
It actually reminds me of Pinegrow in that it works with native source files and allows for full GUI manipulation, however it's GUI in certain areas is more straight forward and intuitive than that of Pinegrow. It also allows for drag and drop positioning, has a nice animation feature, etc. For the cost it may be worth checking out to see if it would benefit you in anyway as part of your toolset.
It certainly is more towards Pinegrow than Blocs however. You need to have knowledge of HTML/CSS/JS to fully leverage it like Pinegrow. But just the same as Pinegrow it offers the opportunity to help learn these things as well.
It has not been updated since mid 2015, and perhaps wont be. But given it's use of HTML5, CSS3, as well as the full ability to work with any framework as raw native sources, it's not really limited in any way even with it not being updated. I had known about it for more than a year and finally got around to checking it out. Much like Pinegrow (or any app) you have to take the time to understand the UI and thought process of the app, but once you comprehend it you may find it useful as tool in your toolbox.
Pinegrow version 3, UI is getting an update and rethinking / facelift, so we will see what that yields as well concerning usability and feature improvements. If you do happen to check out Xpressive, I would be curious what you think.
Likewise very excited to see Blocs continue to advance as well this year.