Devices, systems, and methods for selectively engaging downhole tool for wellbore operations

A device for wellbore operations is configured to self-determine its downhole location in a wellbore in real-time and to self-activate upon arrival at a preselected target location. In embodiments, the device is configured to self-determine its direction of travel and self-deactivates if the device determines that it is not travelling in the downhole direction. In embodiments, the device has a flowback valve that blocks fluid flow therethrough when the device is inactivated but permits fluid flow through the device to exit at the device's trailing end when the device is activated. In embodiments, at least a portion of the device is dissolvable in the presence of wellbore fluids. In embodiments, at least a portion of the device is coated with a protective coating to shield the device from treatment fluids. A downhole tool having a pass-through constriction configured to be overcome by the device is also disclosed.