Andrew, I forgot to mention that I changed the "Reset All" button to just read "Reset" for a very good reason. Other languages that already have a "Reset" translation in the po file, will automatically have this already translated too. For example, in German Reset already has the translation of Zurücksetzen. So this button is consistent with other plugins like Crop & Position and Crikey. Also reworded the tooltip a little. Am a little confused about the change to DEFAULT_TIMECODEFORMAT TIME_HMSF but I am not fussy.
RafaMar, I also checked in the small change to es.po that was dated January 22.
Moving on: now am hoping to look at the mods for multiple backups and how to add in the batch render pdf information. Andrea suggested adding it to the manual after the Quick Start but that would be in English. However, adding it to ShellCommands would work with some effort -- IgorUbuntu in June 2018 added ShellCmds_ru.html to describe how to use the shell commands (button in main window, upper right hand corner) in Russian with the default in English and other languages to be added as provided. (See {where cinelerra is}/cinelerra-5.1/doc/ShellCmds.html) but I tested that today and it looks like with the mod for Settings->Preferences, Appearance tab changing language, that there is something wrong.