SIGN_ERR01 when updating

Not really, you could try auto-installing 1.19 maps.
It should work without reformat, although I do not recall any previous case, since most autoinstall cases are for EU and NA, you can take this thread as reference → Tutorial: 2020 North America 2.20 Map Installation (Stand-Alone without Reformat) with Updated NAV_Voice 06/21/2021