I forgot how brilliant the bootstrap blocks included with Pinegrow are.
Initially I found it difficult to customise, but after spending the last 6 months or so learning about CSS, HTML5 and Bootstrap, once you return to PInegrow and use the included Block Kit, you realise why it was included by professionals.
If you have struggled to get to grips with Pinegrow and blocks, I urge you to start building your own blocks (even if they look crap at first) because it gives you that knowledge to use the block kits for their intended purpose, rapid development of websites or mock-ups, while allowing you to build websites that look custom made.