I thinking of doing the same thing. I saw that tee with the POL female and male. my 2 stage regulator has a 1/4 npt female inlet. So I'd have to reduce it down coming out of the tee.
Yes, most 2 stage reg have a 1/4 inch fem NPT. Im using a POL pigtail like this
.. BUT you will also need this adapter…
I got the same pigtail but 2' in length. I also purchased the 1/4" adapter with back flow preventer.