[cem] Quick Question about implementing different CEM specifications for each treatment observation

Dear CEM List members, I have about 45 treatment firms and I am trying to create a control sample. Using that control sample, we plan to collect additional information about the firm, which would take some time and effort. I was wondering if I could use different CEM specifications for each treatment firm to get the most accurate control firms. The issue is that for some treatment firms, I get a huge strata, on the other hand, for other groups I have two control firms. I was wondering if I could use a more stringent matching criteria for those treatment firms with large number of control firms and a less stringent matching criteria for those that have a low number of control firms. My concern is how would I run a regression later because the weights are derived from different matching specifications. Or does it matter? Thank you for your time and consideration. Kind Regards, Pureum Kim