I'm on the same boat as you are right now, I'm creating web 2.0s meanwhile building a PBN, i have to say Web 2.0s should not be your main link building options because they pass very little juice nowadays. The good thing with Web 2.0s is that they gain PA really fast but you will need tools like GSA SER to juice them up. They should also be treated like your MS, 8-12 Quality human readable articles with 2-3 static pages (About, Contact, Social Media....) per web 2.0 and make sure everything is RANDOM to leave no footprints.
My strategy so far:
I bought a list of emails from fiverr to use (Different email per site, stay away from Gmail).
I installed LastPass Addon to keep track of all passwords and emails, might as well make a csv file.
The web 2.0s I'm aiming for are: Wordpress, Tumblr, Weebly, Wix, Livejournal, Jimdo, Blogspot (even though it's a Google service...) and more...
I would advice to use a VPN and switch servers for each site, it's safer to use different IPs per site.
A good start would be 10 Web 2.0s, creating 3-4 everyday.
MAKE THEM LOOK NATURAL, It's crucial for their success, have an Author's name and info (use fakenamegenerator.com for that).
Adding an author's picture and social media would also help (Get a picture of a random dude from G, and niche relevant FB, IG pages).
Create at least 2 static pages titling them differently for each site (ie: About me, About the author, About Joe | Contact me, Contact Joe, Get in touch).
Scrape the content with Kontent Machine if you have it, or write a quick 100-200 words yourself.
Add images with keywords in the alt tags, create a quick logo online for you site, make the design look neat and natural.
----Articles----
Articles are the holy grail of web 2.0s, they'll either make you or break you, i definitely advise against scraping content for your T1s.
I usually use buzzsumo to get relevant articles to my keywords, except the articles should be in other languages such as French or Spanish.
I translate the article to english and give it a quick read and fix any grammar errors, i then run a plagiarism check to make sure they're 100% unique.
I also add images, YT videos, 2 images 1 youtube video, no media at all, JUST KEEP IT RANDOM.
I add anchors to my articles, 30% linking to my site and a 70% linking to relevant authority sites to camouflage mine.
I would advise creating a folder with over 30 articles saved in notepads, then simply copy-paste to your site, that is time efficient.
I Schedule all posts to my web 2.0s (8-12 articles per site) over a period of 2 weeks, different posting time for each article, make it RANDOM.
Some articles should have no links to your site, some should have no links at all, some should have images, some should have videos. RANDOM
After about 2-3 weeks, once all web 2.0s posted their content, I would start a 2nd tier campaign with GSA SER and keep it running.
Results should start showing about 2 weeks after starting GSA but make sure web 2.0s are not your only backlinks.
Biggest advice, Make them high quality, just like your Moneysite for best results and keep everything RANDOM
Useful reads: gotchseo.com/manual-web-2-0-creation