They do, but they don't allow sequential pulling of match data. I would have to collect my own data and poll their API with each match id to get the MMR estima

They do, but they don't allow sequential pulling of match data. I would have to collect my own data and poll their API with each match id to get the MMR estimate. Although that works in theory, their API rate limit is 3/s and last time I checked there were about 1M matches / day (~12/s) so we couldn't keep up.