Did we ever settle whether one has to register a sub 255g aircraft if used commercially?
Out of meetings and now can give a little bit more "background" as to why Part 107 requires Registration regardless of weight of the aircraft:
Part 107 Registration
§107.13 requires a Part 107 UAS be registered in accordance with §91.203(a)(2).
§91.203(a)(2) states that no person may operate a civil aircraft unless it has …an effective U.S. Registration certificate applied for under §47.31(c) and provided for in §48.
§48.110 provides information on how the registration will be handled. For example, each UAS will have its own registration number and how long the registration is valid for. This section also gives no relief for weight. Because §107.13 drives you to §91.203(a)(2), there is no relief for registration based on weight.
Recreational/Hobby Registration
Now, compare that with recreational flyers operating under the “exception” (Section 44809). Those aircraft must be registered in accordance U.S.C. Title 49 Chapter 441. In this case, §48.15 then takes the lead (
not §91.203(a)(2)) which does have relief for weight.
Conclusion:
Since the regs do not "allow" for a min weight to be registered every sUAS (in the USA) that is flown for Part 107 operations each one must be registered and labeled with a Commercial Reg #. It doesn't matter if it's 1gr if it's used under Part 107 it much be registered and labeled for Part 107 ops.
Hopefully this makes some sense and isn't' total gibberish LOL