sure, but please bring it to pm, it is against TPT policy to post the sale related topic here.
and before you switch to double stage, I want to make it clear, I don't against single stage systems, and I think your current setup is fine, the stainless steel regulator is a high quality Parker Hannifin IR4000 series, $500-$600 retail...
here is a recent pm that I answer one of the TPT member.
End of tank dump is rare,
and it only cause trouble due to some certain condition.
1. not enough aeration
2. original co2 injection was at high level
3. the output pressure setting on the regulator is LOW.
4. a regulator failure
5. user error
all single stage regulators have OUTPUT PRESSURE RISE, but seldom cause trouble, because the output pressure rise is about 0.1psi for every 100 psi input pressure drop, and a low quality one, is about 0.5psi for every 100 psi. either case, output pressure rise can never be a big number.
If everything is setting up right in the first place for a quality unit, due to output pressure rise, you will still have excess co2 injection while the co2 tank pressure dropping, to fix this problem, is all about the #3. keep the output pressure above 30+ psi, the excess co2 injection is a really small percentage when the co2 tank pressure dropping.
#4 are actually the main cause of fish death, the low quality regulators have trouble to respond to the slowly dropping pressure due to none responsive diaphragm or poppet valve spring, and cause large amount of co2 "rushing".
I don't against single stage systems, but only criticize the quality of some units, because EOTD is like shark bite, scary but only less than 60 people got killed within a decade...
search the forum "output pressure rise bettatail", you will see more detail info about what I see the EOTD, and what is the difference between the double stage and single stage systems.
I admit I am wrong on the part that less than 60 fatality within a decade, the actual fatal rate is much less..
and I forgot to add that a needle or metering valve can act as a "manually controlled" pressure valve(control the flow volume of co2, which in turn affect the pressure differential), if the needle has less precision and orifice size changed by any reason, may cause excess co2 injection as well.