For sure, innovations that were combat proven were - sooner or later-picked up,
but sometimes there were technical issues or even N.I.H. [not invented here]
problems..
For example, the damage done by Bf 109 20mm cannon fire impressed the Brits sufficiently to get them moving on installing their own, & while the lighter Spitfire got 2, other heavier fighters [ including the early Brit ordered Mustangs] got 4..[even the Brit ordered P-39 had one in place of the 37mm].
Problems with the US made Hispano put off the USAAF from using more of them,[1 in the P-38, but 4 in the P-61] & the USN was always more keen..
When the Tizard delegation brought the many Brit technical developments over to the US - some companies were definitely more proactive in adopting advancements, Grumman & N.A. Aviation amongst them..
The Merlin P-51s picked up the Brit -type coordinated engine management controls but the US radial fighters missed out on the German Kommando-Gerat equivalent as used on the BMW powered FW 190..
On the `51H serviceability issues, it is very probable that the SAC [ given boss C. Le May's hard-ass rep] had a better grip on them than the 'weekend warrior' ANG fly boys..