Literature survey in multiple languages
I would not do a multi-language literature search for Master's degree (due to limited time, as you mentioned, plus simply because expectations for a Master's level of research are significantly lower than the one of Ph.D. level. Having said that, I've seen some pretty solid research-focused Master's theses, but they are relatively rare.

On the other hand, performing a multi-language literature review for a Ph.D. research seems like a good idea, as it would allow you to cover the topic as well as related fields of study and research streams much more comprehensively (in both width and depth), which is an expectation for a doctoral-level research. However, you should always be focused on your main goals and assess your literature search with overall Ph.D. program's and dissertation's time frames in mind. It is so very easy to get addicted to exploring vast volumes of existing research, even restricting yourself to a particular subject domain. That introduces the risk of spending way too much time on that, jeopardizing other essential parts of your research study. You have been warned! And good luck!