What if the Arial Target had been developed quicker, was available for some of the last Zeppelin raids on the UK and successfully brought one or more down, would that have any longer term effects?
I doubt it would be possible. The technology simply wasn't advanced enough for such weapon to be reliable. Low was extremely talented men, but no talent alone could circumvent the limitation of technology.
The main problem with AT was, that it used a very primitive radio control method - the pulse position modulation. Basically each control cycle was divided into time slots, and each command (there were six - up, down, right, left, engine throttle, detonation) was assigned a specific fraction of second time slot. To send the command to the AT, the ground control station sent a single radio pulse exactly at the right time slot for this specific command. For that purpose, both the transmitter (on ground control station) and receiver (on AT) were synchronized by rotating camshafts, which rotation speed were carefully synchronized before launch.
The inherited problem of such system is that it's self-contradictory. To ensure good synchronization, the time slots should be relatively big - but then less command could be sent in the same time, the delays would be significant and the whole system would be slow to react. To ensure good control, the time slots should be short (so they could be repeated as fast as possible) - but then the synchronization would suffer, because even slight differences in camshafts rotation speed would cause control signals to "miss" the intended positions.
Essentially, this system was suitable for something relatively slow - like target ship - but for airplane it was next thing to useless.