Is there any at least theoretical way to get rid of the "passive" or parasitic capacitance of the capsule. By using bootstrap, or negative capacitance?
This is a question more than a suggestion / solution, but might the charge amplifier setup influence the input capacitance in any positive way?
https://audioimprov.com/AudioImprov/Mics/Entries/2015/12/20_Modding_a_BM-800_Mic.html
Upon some further thinking, it might even increase it, but... my knowledge about the finer points of discrete circuit design is failing me on this