The USAAF requested the use of OBOE and GEE-H, so it can't have all been bad!
View attachment 623187
That was provided to me by the late Edgar Brooks some years ago.
These were mostly used for target marking by Mosquitoes. The main bomber force would then aim for, or between, those markers.
As I understand it, OBOE and GEE-H had accuracy comparable to daylight visual aiming.
The limitation with these systems vs visual aiming was range. Though the British did experiment with a repeater aircraft to extend the range.
The external tanks normally used were 50UKG.
The calculations I made years ago were based on a Mk.IV with 4 x 500lb bombs.
At 6,000ft the Mk.IV was capable of 340mph at 9psi boost, 95% of maximum load, fitted with ejector exhausts but without wing tanks.
I don't have enough information to answer that, other than it was at least to Berlin - around 600 miles radius.
I don't have any performance numbers for the B.XVI, but the B.IX was similar had had a speed of around 345mph @ 5,000ft with two 500lb bombs under the wing at 95% of take-off weight, with +18psi boost. With +21 psi boost the top speed jumps to 365mph.
http://www.wwiiaircraftperformance.org/mosquito/lr495-b-level.jpg
If a low altitude mission was deemed the best, the high altitude 70 series Merlins could have been replaced by the mid-altitude Merlin 66s, equivalent to the V-1650-7.