Hi,
First, do you follow architecture layer when developing apps ? If not, better use architecture layer so the component in a module will not become too complex or too big. (https://success.outsystems.com/Documentation/Best_Practices/Architecture/From_architecture_to_development)
Second, I got this from Outsystems support but not sure to find this on the Outsystem's Documentation, but its better to hava a single module about 4 MB per module. You can check this by saving the module as .oml file and see how big is the .oml file.
Thanks