First of all we'd like to thank you for your interest in BITalino... indeed it may be a valid concern.
The BITalino ECG sensors have the gain in 2 stages (~10x + ~100x); if you want we can produce ECG sensor as per your specifications (e.g. without the first stage which would be ensured by the Plessey Semiconductor PS25255).
Perhaps you could even consider purchasing two sensors (a standard and an altered one) and you can test both configurations. Depending on the sensor placement (e.g. with the electrodes very close together) a higher gain may useful.
In order to proceed with such a custom setting, the best is to e-mail us to firstname.lastname@example.org
The BITalino Team