The mythic stats tool is currently in active development and is not currently publicly available.
Mythic user stats is a Chrome/Firefox extension for displaying stats for players in Mythic League. This data is pulled from my own custom API, which uses the data from the Mythic Match Dashboard.
The Extension has support for limiting the number of matches, allowing you to limit to the last 20, 2000, or anywhere in-between. You can see a persons HS across their entire Mythic Career. Or maybe check their KD for the last 20 mythic matches so data for those "freelo" matches is excluded.