There are certain individuals that are in your face selling their products/training and it has caused a negative reaction on Bigger Pockets if certain individuals were promoting Sub2.

flipping is very tough right now - materials are expensive, good contractors are booked up, interest rates are high, buyers are picky. 

A few personal favorites are Facebook Market, Homegoods, Wayfair (for certain items and materials), Rooms to go. local furniture/cosignment stores, CB2 outlet. 

Links to your three other posts on this same topic so readers can see what's already been discussed:https://www.biggerpockets.com/forums/61/topics/551577-backyard-homes-produced-in-chinahttps://www.biggerpockets.com/forums/617/topics/551580-china-built-backyard-homes-socalhttps://www.biggerpockets.com/forums/61/topics/537480-tiny-homes-produced-in-chinaThis sort of house is an interest of mine, though I'm more interested in building them on-site with a 3D printer and local materials.  

Make sure to checkout all the materials under the "learn" tab, especially the podcats, great for those long commutes.

Just about anyone can get on this site and promote their services.

How is material participation defined?

I had a whole incubator program I called "0-Hero" where I would train a person in everything, literally everything, from 0, and promoted best part was no buyer-list needed or struggle to find $ because that was me, done, ready to go just do the steps. 

If he is not eligible to claim REP status, is he eligible to claim he materially participates in the deals (even the ones with <5% ownership)?

Better pricing on material?