Looking through the Guide to Awards and Insignia for the words “temporary insignia,” I did not find a definitive reference that only authorized patches can be worn as temporary insignia.
Patches earned with (awarded by) a different organization do not qualify as temporary insignia.
The general rule is that badges awarded by organizations other than the Boy Scouts of America (BSA) may not be worn on an official uniform. This includes military medals and service ribbons.
Temporary insignia are issued by different levels in BSA scouting, page 11-12. It does not say that ALL temporary insignia MUST be issued by some level of BSA scouting.
Temporary insignia are issued for such events as summer camp, camporees, and Scouting shows. Order of the Arrow regional and national meetings and training activities may also provide such insignia (the Totin’ Chip patch is also temporary insignia).
The closest thing I found was on page 12. Initial reading is that every patch must be a BSA authorized patch. However, this is qualified in paragraph three to mean that all Scouting patches must be officially approved and sourced, including council approved temporary patches. This makes the reading seem to be “All regular uniform patches and scouting temporary patches must be officially approved and sourced.”
It is mandatory that all patches, emblems, and other products worn on the BSA uniform or created for a Scouting event or activity be obtained from official sources, such as Scout shops and www.scoutshop.org or a BSA licensee at www.licensingbsa.org.
Badges of rank, advancement, position, patrol, or numerals that are manufactured or authorized by the Boy Scouts of America as official patches do not require corporate identification.
This means that all council-approved badges for Cub Scout, Scout, and Venturing events and activities must also bear a BSA identification to help protect the BSA brand, and must be obtained from an official source authorized by the National Supply Group.
Page 15 provides guidelines for some level of BSA scouting to make custom scouting patches. It does not limit temporary patches to only BSA sources.
Further comments of temporary insignia refer to specific patches.