José Adorno/BGR Last year, unreleased code suggested that Touch ID could be coming to a future iteration of the Apple Watch . As spotted by Macworld's Filipe Espósito, the company was experimenting with a biometric unlocking mechanism to supplement the current passcode-based authentication system. While the journalist said that this was still in the early days of testing, MacRumors  subsequently reported that the change could come as soon as this year.  Now, Weibo leaker  Instant Digital  is pushing back against both of these reports, saying that Apple doesn't plan to make a radical change to how users unlock their watches since the hardware required for this authentication method could take away precious battery space. In the post, Instant Digital suggests that Apple doesn't like the idea of losing battery life in exchange for Touch ID, nor does it find the extra costs associated with adding this technology palatable.…