You do not need Class A volumetric glassware at this scale, it's not going to provide that much accuracy vs a Class B.
Reef central needs to realize that KH from CO3's in FW is quite different that KH in marine systems. They have multiple components in their alkalinity, it's not all carbonate.
So that is not a good standard for them.
They likely would be better off using a digital tritrator etc.
Making up an accurate alk ref solution for them is tougher.
Most alk test are total alkalinity test, not carbonate specific, hence our problem, but works fairly well in a marine tank.
Our issue is highly specific to carbonate only.
The other alk species confound our FW plant/CO2 readings for a lot of folks using KH test kits.
The Salty folks may still use the KH ref solution and drop checkers to measure CO2 in their tanks though.
But they generally are less concerned about that and they would need a higher pH indicator(7.0-8.2 range) as few add 20-30ppm of CO2
Regards,
Tom Barr