Hey Almo, indeed it’s been some time ^^
I can only reiterate your point about the wide spectrum that WBTB can take. I read several guides and topics and discussed with people and everyone does something different. So there seems to be no golden rule for WBTB.
I guess the important point is to influence your sleeping cycle correctly with it and set up your brain chemistry in a favorable way? Plus you can do some induction technique right before dreaming prime time (the last sleeping cycle(s)).
So to me it seems that you’ll want to wake up as cleanly as possible from a sleeping cycle (like at the end of REM) and do that naturally rather than with an alarm may be beneficial. Or it may not, so don’t get worked up over that. Then you’ll want to do anything that increases your chance of inducing a lucid dream and avoid everything that will prevent you from falling asleep again smoothly.
As for the effectiveness, unless you are messing up your timing badly, WBTB is pretty much guaranteed to improve your chances. And enough so to warrant the effort it costs, if you manage to tune it to your needs.
Ok, here comes my personal report. WBTB does not guarantee me lucid dreams and measuring its effectiveness is actually quite hard because I’m not a particularly regular lucid dreamer. I think I counted 31 lucid dreams this year so far, out of which 2-3 were after WBTB. I only made about 10 serious WBTB attempts though. Maybe about half of the LDs were spontaneous DILDs without intentional induction. Funnily enough, I also had 1 or 2 LDs before waking up for the WBTB. The reason is probably that I do MILD when going to bed also when I plan to do WBTB that night.
If I do a full commitment WBTB then I plan 1 to 1 1/2 extra hours of sleep. I set my WBTB alarm so it wakes me up about 2 1/2 hours before my final alarm. That way I am pretty sure that I wake up after my second last sleeping cycle. I’m pretty accurate with my timing and usually wake up naturally 10-20min before the alarm. Multiple times I woke up about 1 minute before the alarm. Then I have about 30 minutes awake, which leaves me with 2 hours for falling asleep and the final sleeping cycle plus a little buffer before my final alarm. If I commit to induction then I prefer not to be awoken by my alarm at the end of sleep because of the danger that it kicks me out of an LD 
Like I said, I do MILD when going to bed in the evening. After waking up for WBTB I firstly write down dreams. In my opinion this is the first most important thing to do because it is easy, gets you in the mood (you can start incubating from a previous dream) and it’s the fundamental technique for anything dreaming related. Then I tend to my body (toilet, maybe drink a little, arrange by bed stuff so I can be comfortable). If I feel that I still have some time then I read something about dreams, mostly on LD4all, can also be DJs. I avoid social stuff like responding on messengers or to e-mails. I do pretty much all of that in bed (except the toilet part
). Then I finally go back to sleep doing MILD. I sometimes attempt WILD but never managed.
My biggest problem is falling back asleep. Usually I don’t fall asleep quickly enough. This could be because I spend too much time awake or simply because I’m too excited at the prospect of having an LD
Sometimes I also fall asleep too fast because I’m too tired and then the induction technique isn’t effective. Another issue is that WBTB nights need to be longer than regular nights and the additional time I can only prepend to my normal pattern. That means I need to go to bed earlier than normal and shift a major part of my sleeping in an unnatural way. So sometimes I don’t fall asleep in time in the evening. I even cancelled WBTB a few times before even getting a minute of sleep because I lied in bed awake for too long.
The reason why I do this so rarely is because it takes a lot of time and it’s incompatible with my wife sleeping next to me. So when I’m on business trips I like to do it or when she’s sleeping out. Also it’s a big commitment and I like to do it properly and avoid messing up my night’s sleep.
I have another kind of WBTB that doesn’t work with alarm. I simply use a natural awakening at whichever time in the night it may happen. I usually wake up about two times each night, so those are natural occurring WBTB opportunities. But often I’m too tired and don’t follow through with WBTB. Instead I usually go back to sleep as fast as possible because otherwise I’m afraid my sleep well be wrecked and the next day I’ll feel horrible. But even without getting up and writing down dreams I can use these Intermezzos to do some induction technique. I want to make this a more reliable habit, but I still require some work on the way.