Again hopefully someone more ROS experienced will chime in!
As you mentioned BLDC is a generic term. As you mentioned the RobotEQ Ros driver is specific to their controllers.
However you can go to their Sources:
And get an idea of what it would take. That is they have code in place that defines some new messages, plus c++ code to talk to their boards. Again depending on how different your controller board is from theirs. You might be able to get some of yours working by simply changing the actual commands and responses that the board sends
Or if your board works more like the Roboclaw, you might look at the ROS driver done for it, which I posted in the earlier response.
Or again you could factor your code completely different. That is you could have a higher level node, maybe one for rover_controller, that maybe does the code that given some form of request, like maybe a new velocity, is responsible for telling your motors to do what is necessary and is also responsible for processing whatever feedback the controller provides (encoders? or the like) and then generate appropriate messages… Internal to that node you can talk to motors using your normal code (C++, Python, …)
An example of this, was code some hexapod robot code that uses Robotis servos,
where the main node, has the code in place to talk the servos. In his case he was using MX servos, where his main board talked to the servos using USB2AX board. I had versions of it that worked with AX12 servos also using USB2AX or Teensy boards or … Internal to that node we were using something like the standard DynamixelSDK (adapted to talk to /dev/ttyACM0 instead of the default /dev/ttyUSB0). Actually my fork of it tries both of these… Actually it first tries /dev/ttyDXL which I at times would setup using udev rules)… Sorry off topic.
The point is here he made the choice to simply encapsulate the motor controller code into his main node, as his code is tightly coupled to how he is talking to the servos…
Again hopefully you might find a driver specific to your setup.