How to increase metabolic rate after weight loss?

Hi, I am currently on a weight loss journey with intermittent fasting and calorie counting. I aim for a 500 calorie deficit each day in terms of what I eat. I am not an expert and there are lot of information out there, so I might get some things wrong, but please bare with me.

1. Many are against excessive calorie restrictions (~1000 calories) because it can cause our bodies to significantly lower our metabolic rate to compensate for the lack of energy. Then, how come a more moderate calorie deficit of 300-500 calories does not lead to the body compensating the same way?
2. After I reach my goal weight on a 500 calorie deficit diet (compared to my TDEE), would my metabolic rate be of a person who needs to eat 500 less calories to maintain their weight? And if so, how do I increase my metabolism after weight loss so that I can eat similar amount of food to others at my weight?

Thanks for the help!