Well, just because you are flat doesn’t mean that you have to stop everything “fat loss-wise”. It is normal to feel flat when trying to lean down and if you increase calories and drastically drop volume for 1-2 weeks everytime you feel flat you will never get super lean. It’s sadly part of the process and it can be a real mind fuck.
That having been said I’m not against a training deload every 4th week, especially if you are the type who needs it.
You might not need to cut out cardio and up calories for 1-2 weeks though (certainly not for 2 weeks). A few days (1-3) with a higher caloric/carbs intake might do (after all you can only store around 400-500g of carbs).
I do use an approach where calories are way down for 3-4 weeks then increased the maintenance (or slightly above) for 1 weeks. But when I use this approach I do use a drastic caloric reduction during the 3-4 dieting weeks. If you do that using only a small deficit you will not progress much.
The interval method of dieting is designed to go REALLY hard for 3 weeks then give your body a break for 1 weeks to avoid the possible downside of severe dieting.