From interested reading over the years, it seems to me that the main conduit for technology transfer on the aviation side was through both the RAE and via technical papers and patents. Do not forget that private companies were in direct competition, even in wartime, I believe Bristol had to be coerced to help Napier sort out the sleeve problems with the Sabre. I am sure that wartime analysis of Axis technology was performed by some R&D departments as and when they saw the need or opportunity. Much information was also published in post-war BIOS and CIOS reports.
Overall, for your purposes, I think that some research about the RAE and its involvement in promoting different aviation technologies with the Government Ministry might be worth a thought? Cheers
OAP