How long does it take for the Yong Heng to get up to pressure? You take that wait on every gun fill opposed to every 20 or whatever fills with a tank. How long does it take to fill opposed the gun opposed to gun? I am genuinely curious. I wanted the fastest fill when shooting, so I went the large carbon fiber tank route.
The efficiency of the gun matters if it interrupts your shooting session (enjoyment). The other part of that is the more efficient your gun is the less time you spend waiting for a compressor either your own or at a scuba store. If you have reliable automatic shut off then that wait for your own compressor may be a non-issue (I understand the relays for auto-shutoff on the Yong Heng are subject to failure, as in the compressor fails to start). My advise is to figure out how much air you go through, and what that means in terms of your time with and without the plenum upgrade. The compressor is a capability while the plenum is an optimization.
When I had my tank filled the first time, it took hours, as they insisted on a visual inspection of my brand new tank, then they filled my tank, and then we waited for it to cool, finally to top it off. If I had to do that often, I would be in the market for a compressor. When my tank is EOL in 15 years, it will cheaper to buy a compressor than re-certify or buy a new tank. Even then the cost of fills ($25?), yearly inspection ($25), and hydro test every 5 years ($60) quickly pays for an inexpensive compressor.