@bekemew I started ranking with expired web 2.0s, then moved into building links with GSA, now I mainly use my time to build PBNs.
Yes, I use web 2.0s in my tier 1 to my moneysite. If it's a site you really value I suggest you build manual web 2.0s and make them look real. Main reason because if you start ranking for really competitive keywords other website owners may look into your link profile and report all your web 2.0s.
But if its not my money site I use RankerX or GSA SEREngines to build the tier 1 web 2.0s. I like GSA SEREngines better solely because the themes on the web 2.0s are chosen at random. But they only have a handful of engines at the moment.
I use spun content from SEO Content Machine on my web 2.0s, just scan it for any big errors and delete those chunks. I know many people are going to disagree and say only use hand-written content on web 2.0s, but everyone has their own opinion. My articles are 99% unique and at least 1000 words.
No, I wouldn't suggest you use GSA directly on your PBN, since it already has powerful links to begin with. If you really want you can build or buy some web 2.0s as a tier 1 for your PBN and then beef those web 2.0s up with GSA contextual links.
As for Google cracking down on PBNs, I'm not worried. How is Google going to tell if it's a real website or PBN? Yes there are many factors but that's why you need to really design your PBN as a real site. Social media accounts, advertisements, press releases. Don't just post 500 word articles in every post. Post pictures or a YouTube video along with a small description.
And also there will always be other methods besides PBN. SEO is always evolving, just need to do your own testing as see what gets you ranking. I play it safe on my money site, but have multiple others tests going on other domains. That way I get to be more aggressive with the link building and don't care if my site tanks, as long as I get a return in profit.