As I understand [forumtopic] well you should start with translating the Glossary. In the past I saw changed translations in the Web making a difference between Web, Seek and the mobile Apps.
Comment (not in the Glossary) is translated e.g in 4 different ways accross the different projects.
Maybe this Glossary shows quick how special technical terms for iNaturalist as Data Quality Assessment , RG, Casual, Verifiable,geoprivacy, open, priviate should be translated. I agree with Carrie that familiarity with iNaturalist is necessary for translating these terms. If you do not have it trial and error was with the old translation system also succesfull.
Goefie translated 50% of the website in a month but it took me three months to translate the rest. So translating all of web and mobile into traditional Chinese should cost me definitely more then 10 days…