yeah, but elevate the front leg on a block if you can so your bdoiy can sink down as it fatigue and stretch out - let it do this. No weights, bodyweight is challanging enough! for 1min. Just one per side. But rest at least 2mins between sides, preferable 3 - you will need it
these work fast, after a few session you should see your hip flexors and glutes much more flexible. Also try and stay as upright as you can, look up a bit
After things improve you just do them after your workout to keep things from regressing.
You might want start doing em a day or 2 ahead of your leg workout, to get the ball rolling fast