Meanwhile, the Ukrainians and US defense suppliers already have a good handle on how to counter the two current models of Shahed and any likely successors. Low, slow, noisy, and cheaply made has them vulnerable to being shot down with standard infantry and antiaircraft weapons and misdirected with electronic countermeasures, while a number of light, palletized, truck borne US Anti UAV Defense systems called Vampire are already in Ukrainian hands and being put to use.
The result is that the Shahed has its effectiveness against defended military targets so the Russians turned to attacks on cities and civilian infrastructure. As the Ukrainians get more Vampire defense systems in place and a supply of its newer, longer range model of missiles, even Ukraine's area targets will be defended against Shaheds and similar weapons.
My guess is that the Shaheds will have lost much of their effectiveness long before Russian language manuals and a full contingent of Russian trainers are available. The US and NATO model of organizational speed and nimbleness in weapons innovation has considerable advantage over stodgier Russian and Iranian capabilities and practices.
Isn't that something? The mighty nato war machine and the gallant nazi hohos humbled and brought to grief and justice by toy airplanes...