I've checked all three of my Mavericks with boiling water. All three were perfectly accurate. Mine don't take that long to get up to temp. Maybe 30 second - 45 seconds. I'm not sure what you're seeing.
I don't think the Mavericks are a commercial or industrial design. They have limitations. But for the price, they are decent.
Proudly Smoking on a UDS, PBC &
Accidental Winner of the 2012 "Saucy" Throwdown.