Does anyone know, if there is a good documentation for these kinds of pins in the Caravan SoC? Since I do have a High Frequency Project That would be quite important to me to get some specs...

Most of the pins along the top of the Caravan chip are straight-through signals with no ESD protection. Those are the best for high frequency signaling, although you are advised to add some amount of ESD protection (whatever you can tolerate and still meet your frequency spec), and also to handle the chip carefully, of course. The pins above are designed for high current, not high frequency. The circuitry underneath the pad is a power clamp circuit that needs to be connected to power and ground (the two inside pins) if you are using the pads for power supply pins. The outer two pins are connected directly to the pad and should take at least 100mA without violating electromigration rules. The connection of the pins at the user project boundary is a triple stack of metals 3, 4, and 5.