I love how people always want to reinvent the wheel. Why do you mock the ones who have brought you something so simple. Practice makes perfect!
For the record I use a 2" PVC exhaust with a ball valve along with 2, 3/4" trade size intakes both with ball valves. Mine holds temps very well.
I appreciate all the time put in by others who have shared their knowledge.
UDS (not so U) UDD, 22.5 OTS, Coming soon: mini UDS & double barreled RFS