Ever since the arrival of thermal, I've followed the same system: spot with the thermal and shoot with something else, Lamp. NV in various guises such as Pard, Archer, Longbow, Wraith, etc. I also invested in a thermal scope but passed that on to my younger shooting partner as zeroing in daylight was a bit of a struggle with my ageing eyes.
Without a doubt, full thermal (spotter and scope) allows very quick acquisition of the target, once spotted. Just lately I've gone back to the thermal/lamp combination with good results and enjoy being able to see the fox as it really is through the scope as opposed to a thermal image. I've run a fox control business for decades and need to remove foxes that are causing problems, rather than just shooting them for sport. and I find that using thermal to spot, (I use a pair of Habroks), then switching to either lamp or NV, (the good old Archer has been seeing some use recently too) works well for me.
For those who shoot foxes for sport rather than as a necessity, does it really matter if now and then a fox slips away because you can't find it when switching from a thermal spotter to the scope? It will be there another night. I've always thought that there should be a balance between quarry and shooter. After a lifetime of fox control, I see the challenge of shooting foxes at night has swung totally in the shooter's favour. Fieldcraft has all but disappeared and considerable sums of money are spent shooting something that has no value.
The thermal/lamp setup still has a small amount of challenge but looking back over many years of dealing with foxes I have to say it has all got a bit clinical nowadays.