OMAD is just another form of intermittent fasting. You don’t have to condense your eating to one meal to get results, just stick to a small window. Even going with an 8 hour eating window is good. I change up what I do about every 4-6 weeks, at least a little, to keep my body from adapting. I do the IF every now and then as part of that.
A few things about it:
The hard part isn’t limiting your meal times, it’s eating ENOUGH during your mealtimes. It’s very easy to get to where you fall well short of your daily intake. I found myself anemic partly as a result of doing this. Not eating enough produces short term results, but it starves your body and will slow your metabolism. When you break out of this, your weight can shoot up since your metabolism takes time to catch up to your eating habits and it stays slow. If you experiment with this, you need to be sure to eat a balanced meal, watch your macros...that means actually TRACKING your meals, not just guessing. Also, it isn’t just about the number of calories...you need balance. Big difference between eating 1700 cals of carbs vs a healthy mix of 50% from healthy carbs (not sugar), 25% protein, 25% from healthy (not saturated) fats. If you can get the carbs down and protein up, it’s a good day, but this is a reasonable balance.
If you aren’t using a meal tracking app like Lose It or My Fitness Pal, you need to. You’ll be surprised.

IF onlyworks if you don’t spike your insulin during the day. That’s where the benefit really comes from. Your body does not burn fat i. the presence of insulin. So, you might try IF and do fine with the eating, but putting sugar in your coffee through the day, or eating fruit at lunch, can prevent anything from happening. Even some veggies can spike insulin, or even sugar substitutes.

You need to find a good starting point for your calorie intake. 2500 is maintenance level for about a 300 lb man. Find some calculators online, figure 1-2 lbs a week, take an average. Then subtract another 100 for leeway. Stick to tracking meals, nail your intake with healthy balance and see how it goes. Then adjust. At 280, I started at 1800 and it was too much, and that was with going to the gym for an hour of cardio 6 days a week.

Above all, learn new things to eat and adopt a lifestyle or things just go back the way they were. It’s diet AND exercise, not just one or the other. Keep at it, you learn a lot by experimenting!