Every off day on my cut was basically keto with low cals, so I've only done 3 days in a row. Still enough to make me a zombie.
Had a group project and my mates hated me since I basically just sat there unable to think or contribute in any way.
Yeah, regular keto is horrible for performance. For the vast majority, carbs are the best fuel for lifting.
On a cut, you need enough protein to not lose muscle from the calorie deficit. That is generally a bit higher than your bulking intake, since you don't have as many carbs that will help you build muscle. I (and many other BBers) go BW x 1.5 grams of protein when I cut.
For fat intake, you just need enough to not fuck up your hormones. Around BW x 0.2 is bare minimum. If you carb cycle as Leangains suggest, you should get this amount of fat as an average between your lifting and off days for the whole week.
Carbs make up the rest of the calories. On Leangains you only eat "real carbs" (starch) on lifting days with the fat as low as you can.
My macros that I used at the end of my cut was:
Lifting days (3x a week): 250 protein, 25 fat, 400 carbs = 2800 calories (maintenance)
Rest days: 270 protein, 75 fat, 50 carbs = 1900 calories (-30% deficit)
For the week that averages out to macros: 45P / 20F / 35C
Leangains or not, if you get the same macros by the end of the week you will have the same end result. The biggest benefits with Leangains is the mental aspect of every lifting day being heavy carb rewards and that you can eat fatty stuff like eggs and bacon on your rest days when fat intake is higher. My rest day intake of 1900 calories may seem super low but if all your carbs are fibrous veggies like broccoli, you will get decently full.