I'm going to ignore this.
I'm going to act under the hypothesis you won't accept in the beginning the very criticism you asked yourself ... but you always are more flexible in the future. Let's say you'll reread the whole thread in six weeks.
My target weight is 100kg (220lb)... what I weighed as a teenager at the end of high-school. Checking a BMI calculator, at 100kg I'd have a BMI of 29.5, which would put me in the category of "overweight", but at 102kg I'd have a BMI of 30, which puts me in the category of "obese".
So my present goal is to
become overweight.

(Instead of obese.)
That IS doing what I recommended. If you feel that saying you're not doing it helps you, be my guest.
You're a bit shorter than me, that's the only
exact bit of information BMI conveys. Don't pay much attention to BMI. It's just a loose reference.
Last Sunday I weighed in at 150.4kg (330.9lb), this morning (Saturday) I weighed 148.8kg (327.4lb)... I have a long way to go.
(Once I achieve my present goal, I can then think about setting a new goal to get my weight into a healthy range.)
12 to 15 months would be the time, but consider to chose ambitious but attainable targets, like losing 17 Kg (37 pounds) and keep your new weight several months.
What does divorcing from the ways our bodies regulate weight even mean?
It looks like you wasn't paying much attention when you was reading, but just for extreme starters, that losing weight is not like quitting smoking. You can't just quit eating. To some this is such an obvious piece of information that they completely fail to understand it.
My body seems to regulate itself to around 150kg (plus or minus 1kg) when I simply eat whatever I want whenever I feel like it. It stays in that range for years on end.
That's what I meant by barriers. It seems you are in the bracket 145-150kg pound more, pound less, and I suspect 153 kg may have been your maximum weight ever -or 340 pounds, if you weighted yourself in the afternoon or evening-.
Let me guess, a shot in the dark, so to speak. If you ate reasonably, you kept 149 Kg. If you started to overeat a bit, your weight went to 150 kg and you felt you had more energy, and if you overate even more you then reached 151 kg, and you felt a bit uncomfortable, a bit sweaty and with some troubles to sleep.
That would mean that you can easily reach 147 kg, 146.8 kg and then the resistance begins (move the values according to the difference in the previous paragraph), mildly at first. You may not detect any trouble until you reach 146 kg, your body start to "starve" and a lot of mechanism to save energy and urge you to get food trigger. You're reaching the lower end of your current weight bracket and your "
what does divorcing from the ways our bodies regulate weight even mean?" may start to answer by itself.
Okay, I'm mad. But maybe my diet plan is just crazy enough to work.
In sight of that phrase, what do you think a dietitian would think about your chances of losing 110 pounds in a single diet period?
I have weighed myself daily when not on a diet. But just observing my weight and how it changes little or no immediate incentive to abstain from indulging in excess food consumption throughout the day, as the increase in weight from a single day's indulgence is of little or no importance in the long run. And the same applies for the next day, and the next, until days of indulgence run into years.
That's the point of doing things the way I've laid out in my plan (although I intend to post a modified version later).
It forces me to pay attention to what I eat, to abstain from over-consumption, because I want to avoid having to semi-fast the following day to compensate for the indulgences of today.
It's all full of short-termed prescriptions in the hope it'd allow you to reach ambitious goals and definitive changes in life style.
And I suppose the best way to cure a broken leg is to not break it.
You got it. You're very cerebral

.
In that case my target of losing 1kg (2.2lb) per week to begin with falls into your "reasonable" range (0.7% of 148kg is 1.036kg). Nice to know that you agree with me!
But you are aware that will make sense only after 10 or 12 weeks of meeting weekly goals without a major fail, aren't you?
I'm not fasting because I fail to meet a target, I'm fasting because it's necessary in order achieve my target. I'm simply using the scale to provide me with an objective (albeit arbitrary) determination of whether or not to fast on any given day in order to remain on-track to meet this target.
Short-termed again.
I'm not avoiding glasses of water or intentionally consuming diuretic substances to get a lower reading on the scale. I keep a glass of water beside my alarm-clock. If I'm thirsty when I wake-up, I drink. If I need to pee when I wake-up, I pee. Then I weigh myself. I'm not trying to manipulate the scale in that way.
Good to now that if someone tells the public "drugs are dangerously addictive" you will stand and shout to him "I don't do drugs!!!!".
And I sincerely doubt that a single day of low-calorie consumption is sufficient to induce Ketosis.
Then you have to learn instead of hold doubts or not. Of course, ketosis at a dangerous level is not easy to reach. But at least be aware of how different levels of ketonemia feel. Be also aware that in that case you will lose some muscular tissue together with the adipose tissue volume you intended to lose.
The diet never ends, otherwise you fall back into old habits and regain the weight.
You are so wrong in many levels here. Your phrase feigns to be realistic but it contains the seed of failure itself, and the knowledge of its failure too.
If I find myself unable to lose weight beyond a certain point I fully intend to back off and concentrate on maintaining my weight (to avoid regaining what I've already lost) for a few weeks before trying again.
Gain 4 or 5 pounds above that certain seemingly insurmountable point and do as you told. That itself can be the difference between success and failure.