We have added some features to our library of computer-aided design codes for design of depressed collectors and to the code for tracing the trajectories of backscattered electrons. In the former case, the process of optimization of depressed potentials is facilitated. The computer code changes the combinations of potentials by controllable amounts. The trajectory tracing code runs the modified input files sequentially and feeds data to post processors. This generates charts of important parameters in the performance of the collectors. The parameter space can, thus, be explored quickly for optimum operation. In the second case, we have automated the iterative simulation of trajectories of primary and secondary electrons, which interact by virtue of their space charge. This is with a view to obtaining enhanced mutual consistency between them. Furthermore, a specified number of orders of backscattered electrons can be traced. These codes have been used for exploring the dependence of depressed collector performance on various geometrical and electrical parameters for megawatt continuous wave power gyrotrons.