i tend to be cynical about pumping, especially since there’s no evidence of it helping with size development in cis men (there is some evidence for it helping with erectile dysfunction, fwiw). personally i feel like it tends to flood the tissues with edema instead of blood, so doesn’t have a great effect on the erectile tissue. ymmv

that said, it’s probably not harmful, so you can do it safely without risking any negative effects

i would recommend you combine it with a good cardio regiment. need a good strong heart for good strong erections!