I needed to run Terminal in x86_64 mode (Rosetta) in parallel with Terminal in arm64 (Apple Silicon native mode), but in the latest versions of macOS, the old way of creating a copy of the Terminal application and selecting Open using Rosetta in Get Info is not available, since Terminal can’t be copied anymore due to security restrictions.
To overcome this, you can use the following command to open any application in Rosetta mode from either Terminal or Automator:
open -a Terminal --new --arch x86_64
This will open a new instance of the Terminal application. To verify Intel emulation mode, running the arch command should output i386 as opposed to arm64 when running natively.
To switch to x86_64 in an already running Terminal session, execute the following command. Note that ~/.zprofile and other shell setup scripts will not be sourced, and the new shell running under x86_64 will inherit the initial shell environment.
arch -arch x86_64 $SHELL