One of the primary frustrations users face is that Coolsand is no longer an active player in the mobile silicon industry. The company was acquired or faded away as the smartphone market consolidated around Qualcomm, MediaTek, and Spreadtrum (now UNISOC). Consequently, official driver support has vanished.
The (often part of the CM2RDA package) is a specialized bit of software designed for technicians who perform "surgery" on feature phones and older Chinese handsets. If you've ever had a "brick" of a phone with a Coolsand or RDA chipset that refused to talk to your PC, this driver is the digital translator that makes it happen. The "Life Saver" for Dead Phones coolsand driver cm2