Thanks for reaching out!

The U.S. Enviornmental Protection Agency recently released information on varroa mite treatments: Advisory on the Applicability of FIFRA and FFDCA for Substances used to Control Varroa Mites in Beehives | US EPA. In their document, there is a question and answer related to your question:

"Is it a violation of FIFRA or FFDCA to sell or distribute food derived from beehives (e.g., honey, comb, wax, propolis, royal jelly, pollen) harvested from beehives treated with unregistered products?

"Pesticide applications to bee colonies may result in pesticide residues in or on food derived from beehives (e.g., honey, and/or honeycomb, wax, propolis, royal jelly, pollen).. Off-the-shelf products that contain active ingredients but are not registered may contain “other ingredients” or may be combined with other substances for which tolerances or exemptions have not been established. Honey that contains residues of a formulation comprised of multiple substances (e.g., an active ingredient and other ingredients) where those residues are not covered by a tolerance or exemption from the requirement of a tolerance, would be considered adulterated. The sale and distribution of adulterated honey would be a violation of the FFDCA.

"For example, although oxalic acid (40 CFR 180.1381), formic acid (40 CFR 180.1178), and thymol (40 CFR 180.1240(a)) have the appropriate tolerance exemptions established for in-hive applications, unregistered products that contain these chemicals may also contain other ingredients or substances that lack a tolerance. Applying those products (alone or in combination) to a beehive may result in pesticide residues from those other ingredients in honey that are not covered by an existing tolerance or exemption under FFDCA. EPA believes it is likely that unregistered products contain other ingredients or substances for which tolerances have not been established under FFDCA."

We don't do much systematic drone comb removal on campus. If both drone comb removal strategies you mentioned (tossing the drone comb or freezing it and then returning it to the hives) work for you, I'd personally be inclined to reuse the wax comb.

Unless you are rearing lots of queens and have dozens or hundreds of mating nucs, I doubt you need to keep the drone comb to increase the number of drones for mating. Queens generally fly further from the hives than drones do (which prevents inbreeding), so increasing the number of drones on your 10-acre plot where your queens are wouldn't necessarily increase the number of drones your queens mate with.

Happy beekeeping!