Was unable to find specific heatsinks for the chips in question (MKR WAN 1310 processor and LoRa). The ones found were either too large or too small. But, somewhat small or large may still work. Meanwhile, for this first effort, purchased these: Amazon.com: Awxlumv 6pcs Small Heatsink 25x25x10mm / 0.98x0.98x0.39inch Aluminum Heat Sink Cooler Radiator with Thermal Conductive Double Sided Tape Cooling for ASUS ROG Ally GPU IC Chips (25mmx25mmx10mm, Black) : Electronics. Cut these to approximate size while paying strict attention to safety, especially for eyes and hands. Fit them over the tops of the chips of a new device without blocking the reset button.
The data flow went well and the data broadcast is confirmed. My hope is that this does the trick regarding over-heating.