What to do??

Filling guns straight from a Yong Heng is a lot less wear than it's intended tank filling purpose and should last a very long time providing periodic basic maintenance such as oil change documenting run time etc... Just Get a good filter for it and always use ice water in a 5 gallon bucket and a better pump. The one included does not seem heavy duty and run a big Vornado fan facing the motor IMHO... YO

It's not intended for filling tanks, lol. A lot of people use them to do it, though (against manufacturer instruction) some VERY successfully. seems proper oil, and cool run temps are they key
 
The Hong yeng being water cooled is a big downside in my opinion. I suppose it’s effective, but I was very surprised when I saw one being used on youtube

You think the same about the 1600$ omega supercharger? With the aquarium pump i know its hokey but it works and many high pressure compressors use water for cooling as its cheap and very effective.
 
Personally I would get the Yong Heng before the power plenum. You can use your rifle without the power plenum but you can't use it without air. It's great if you have a shop to get your tank filled at but how much of a PITA is it to take it there?

I agree if its between the two id get the compressor first. But OP if you think that the pp is only adding 10 shots you're way off.
 
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.