RJPEG's as far as I know do not have RJPEG as a file extension.
Notice an DJI XT2
View attachment 14228
The R is just part of the naming scheme, not the file type.
FLIR Handheld X Series
View attachment 14229
Parrot Anafi Thermal
View attachment 14230
The way I tell if it is RJPEG is if it works in FLIR Tools. If it does, then I know its an RJPEG.
Also are we sure that the 640 Dual R is not doing something similar to what the Parrot Anafi Thermal was doing? Where the RGB and Thermal Image were combined into one image. Then in FLIR Tools you could separate them or keep them as is.
View attachment 14232
Look where I have it circled in the top left-hand corner. See if these options are available, if so then the RGB and thermal are together, and this offers some cool advantages such as:
MSX
View attachment 14233
Thermal
View attachment 14234
Fusion
View attachment 14235
Blended
View attachment 14236
PNP
View attachment 14237
When I get time I will process the images from the Rectangle folder in Agisoft Metashape. I have jumped ship from Pix4D, as Agisoft's Tiled models blow the doors off of Pix 4 Ds models. Also Agi has Geoid 18 available which added some time consuming steps to Pix4D.