From what I understand it grows wild on the east side of Costa Rica at low to mid elevations. So in nature it would have a 2-3 month period (feb-april) with reduced humidity and rainfall. That dry season is variable there with neither a month or two of no rain nor occasional rains all year long not being unheard of. I have one in my garden that gets watered whenever my potted plants seem to need water and it's doing fairly well blooming more with each year.
Even with M. tenufolia I don't think a strict dry rest is necessary as I just got a big plant this year from a lady who waters all her orchids whenever more than 2 days without rain pass. When I asked her if she had the Maxillaria that smelled like coconut she gave me a huge chunk just because it's growing so fast for her that she need to make some space.