Reddit mentions of Intertap Stout Spout

I am thinking of buying a nitro tank and regulator so that I could add the ability to brew up a Nitrogen Stout, but before I do this I want to make sure I understand the process

In another thread I saw people saying that the best way to do it was to force carb the beer to your desired Co2 level (lower than normal), then switch to the beer-gas and crank the PSI up to 25-30 and serve through a tap with a restrictor plate. Since I have an intertap setup I was going to buy this and use it. Does that sound correct so far?

Assuming that will work, my question is if I am trying to get a specific Co2 volume in my beer, say ~1.8lbs, is there a way I can calculate this based on PSI force carbing time? I'm not sure exactly how to math out how to aim for a specific Co2 volume. I normally force carb at 30PSI for 2-days like most people, and my Keezer is 38degrees if temperature matters

Thanks for any help

EDIT: I found this pdf by Northern Brewer and on page 2 it has a chart, and it says around 5 PSI for force carbonation and those temperatures. But it doesn't list a time, is it correct and is it 2-days, 2 weeks?

I had a brewing buddy do a lot of research on this. Nitro beer's gas is 25% CO2/ 75% N. He charged the kegs at 30psi. Here is the important part. Nitrogen wants to stay in solution unlike CO2 so you have to dispense it though an faucet for nitrogen. You can DIY by rigging a stout intertap to a faucet with hose and clamps (See link) or just buy the whole faucet. There is a screen will small holes that the beer rushes though forcing the nitrogen out giving you that creamy cascade of bubbles.

https://www.amazon.com/Strange-Brew-D1213-Intertap-Stout/dp/B01MS1N42U/ref=sr_1_1?keywords=Intertap+Stout+Spout&qid=1556908067&s=gateway&sr=8-1