I read this directly on the CLS website. It is under FAQs and the subheader "I participated in a previous CLS institute. Provided that I meet the other eligibility requirements, can I apply again?" But I am unaware of whether or not this applies to 2021 virtual institutes. I did CLS Hindi virtually last year and am a finalist for the virtual institute again this year. I have said yes, but
if this is true it does make me a little sad that a virtual program will count towards the limit as what I really desire is to study my target language in the region.