They are derived from internal functions, I doubt you could build your own alternative since they don't allow for variables in functions. It would not be hard for them to allow for a check box that just preferred 64 bit counters.
If you have a 10gb link averaging 300mbps.That is the 32 bit counters will be rolling over in less than 2 if you probe the counter ever 1 minute. Every other time you read the counter it will have rolled over causing a downward spike then the very next read is accurate. Makes the graphs look terrible.
Found on the internet...
100 mbit/sec = 100,000,000 bits/sec = 12,500,000 bytes/sec
2^32 bytes = 4,294,967,296
2^32 / 12,500,000 = 343 seconds = 5.72 minutes between counter flips
Or, at about 105 mbits/sec, you lose the ability to accurately calculate usage in 5 minute samplings.
2^64 bytes = 18,446,744,073,709,551,616 (18 ?septillion?)
2^64 / 12,500,000 = 1,475,739,525,896 seconds = 46,763 years
So yeah we need updates... we have 30 links are converting to 10gb this year.