Pressurized Plastic Fermentor?

So I'm really jealous of brewpubs that can use large serving tanks instead of multiple kegs and prefer naturally carbonated beers. This led me to find out about keg fermentation and Spunding Valves. I've read of Spunding Valves on kegs, but I am wondering if I could just treat an HDPE Inductor Tank/Fermenter as a large serving tank. It makes so much sense because they have so much less work to do and need less time grain to glass if they're spunding. I've looked into it and from everything I've found HDPE should have no problem with higher pressures, does this make sense our just sound crazy?

The fermentor could be elevated above the tap for serving (no engine necessary) with a CO2 tank attached to keep the beer from oxidizing. Basically it just becomes an ugly but hopefully functioning cask/keg depending on the beer style. Does anything besides being a cheap skate stand out as off?

Obviously this only makes sense if you're brewing batches larger than a keg, and then chilling to serving temps becomes an issue. Could possibly try a built in immersion chiller if it doesn't fit in a fridge. If this still makes sense in a few months when I'm back from traveling I'm going to try it out.

Well I think if you're serving English styles it shouldn't be a problem. I am not so sure I'd want to serve something like a saison or other highly carbonated beer like that, personally. I guess I am curious why you wouldn't just use a sanke keg for this purpose? Is it a cost thing? I am sure you could carb a sanke to whatever pressure you wanted, within reason.

Well it only makes sense if it's larger than a keg, otherwise fermenting in the keg seems the way to go. The amount of work and materials for a multiple barrel batch would make converting a fermentor worth it. It's like making your fermentor a brite tank without spending you entire life's savings on one.

How big is your brewing system? I would think that would put an upper limit on your brite tank size unless you are doing multiple batches into a single fermenter.

For my own purposes, if I were going to do something like that, I would have a completely separate brite tank that is the clearing/serving vessel, and multiple fermenters that I could transfer over to it. Otherwise, you are going to run into pipeline issues when you are still drinking your beer but don't have the capacity to get another batch ready to serve when you run out.

Currently at 10 gallons but I'm looking to go bigger.