IMO maintenance is an underdiscussed aspect of IF and weight loss. In preparing for the day I have to maintain, I’ve asked a lot of folks who lose and maintain what their process is.
The #1 answer is that they keep doing some sort of IF. What you’re thinking is what I’ve heard from the successful maintainers. They go to shorter fasting windows, more calories in eating windows. I’ve heard of someone doing 5 days per week of 16:8 and count calories to maintenance and then go easy on weekends.
Congratulations on hitting your goals. Always great news. I think your regimen for maintenance is something you need to hone in on over time. Try some of the things you talked about. See what you’re comfortable with and what works. Vigilance to make sure you’re staying in a range is always a plus if it is important to stay at your target weight.
Once you get into the rhythm, there is no reason to stop. I know I can’t go back to eating all day, it just doesn’t feel right, I’ve been doing this for too long. To me getting into the rhythm is what makes IF sustainable to begin with. Your weight will locate to number that works with what you eat, I would not worry about it, generally speaking. It gets harder to continue losing weight at the lighter end of the spectrum. You can certainly open up your windows but I wouldn’t force myself to eat more food. Full disclosure I am not a competitive athlete looking to make a weight or compete in a certain weight class, if that were the case I’d follow the recommendations of my coach. Congrats to you for hitting your goals, you are an inspiration to all of us!