Whatever we do with respect to the user agent won't be included in the security slider. If that's an issue then it's a privacy issue and Tor Browser's privacy guarantees are or should be the same for everyone regardless of the security level. The slider is for adjusting the security against browser exploitation.

Запретившим выполнение скриптов не положено иметь больше приватности, чем остальным пользователям.