If you’re driving around at a fairly constant weight and no constantly loading and unloading I would bypass all that stuff and run a line with a schrader on it to each bag and then land the schrader somewhere easily accessible.
That’s how I run the bags on all my rigs(heavy heavy 1 ton rigs). I check the pressure with a gauge the same time I check my tire reassure. I have a compressor on my truck to air up if needed. A little 12v tire inflation compressor will work just fine. But you can air up at a service stations also. I drive a LOT of brutal rough roads and don’t have any issues with leaks. It’s simple and reliable
https://www.amazon.com/dp/B08BJ57PDS/ref=cm_sw_r_cp_awdb_imm_VHCX3CCCACV3XQ465R94
Run the lines directly to your bags and don’t T them together. One line for each bag.
The air lines are normally a kind of thick plastic shown in the link below. I personally perfer metal tees but due to winter we use plastic often.
https://www.amazon.com/Hromee-Suspension-Fittings-Replacement-Components/dp/B08BJ57PDS