Is it safe to place heat sink such that it joins multiple voltage regulators?

Solution 1:

Those are actually inductors. The Voltage regulator is basically a LRC circuit with a mofset controller

The purpose of these are to:

The Voltage Regulator Module or VRM is a device that performs DC-DC conversion (DC = Direct Current). This conversion is fundamental because many chips, like the GPU in our case, do not operate at 12V or 5V but at lower voltages like 1V. Then devices to reduce the voltage are required and these devices are the famous VRMs. So a VRM is a DC-DC converter. The other goal of a VRM is to provide a constant DC output voltage as well as providing a lot of current (amperes) to the GPU.

Picture and quote courtesy of Geeks3d

The reason that I bring this up, is that adding a heatsink to the inductors, probably isn't going to be all that advantageous. Adding a heatsink to the mofset controllers, would probably prove more useful, especially if you plan on overclocking your GPU.

As far as your original concern, I don't think that there's an issue of spanning the heatsinks across the inductors, as they are typically in a protective covering that is of high resistance.

Solution 2:

My first concern would be one of introducing noise into the environment if you do this. Noise would come from alternating current though, and not direct current. The voltage regulators will be regulating DC, so there is no issue there. Based off of your picture you won't hurt anything. I thought you question was, "My GPU cooler will overhang the GPU and make contact with some voltage regulators." This will work without issue.