I see what you mean about the desensitization to stimuli, also had a look at part of the N2D2 discussion. It certainly makes sense. Still, I think you are probably having two forces at work here and they are opposing each other - desensitization vs expectation/conditioning. I did shortly experiment with sound alarms (auto snooze and also one playing song), but haven't made it to the lucid phase there. It would either wake me up as it was too loud or it would make me so nervous, I would wake up on my own, wondering when the next alarm will be. And then at some point I would go into deeper sleep, missing it altogether. Possibly in the long term there is some desensitization, as you guys have already mentioned in the other thread. But then you also learn how to deal better with the signal, you know to associate this with lucidity, which builds expectations and is also incorporated in dreams. I wouldn't be surprised if you do this for a long time and start having more dreams with the vibe even if you are not having a vibe night.

About caffeine, I mostly keep my daytime dosages low, so maybe this helps me avoid becoming desensitized. In the beginning, I actually took larger doses, but saw this may be having a neg impact on stability as it was preventing me to fall properly into sleep. Now, I'm more into the 30-50 mg range. I don't do it every day either, so that possibly helps.

Congrats on the ld! Those FAs can be very tricky, had a number of them myself today too (no ld though). We lucid dreamers have to be constantly alert and RCing upon waking because these things are such a great opportunity for bonus lds.