Walking with jogging stroller

So I just picked up a used BOB Ironman stroller, my LO is 3.5 months and I don’t have a bucket car seat (just wear/carry everywhere and use convertible car seat). I’m wanting input on whether it’s ok to WALK with my LO in the stroller without a bucket seat attached (like in the actual stroller. Neck stability is good but won’t be taking him running in it till 6-8months/when Dr gives ok. I’d love to start taking him for strolls in it to get him used to riding in it for a few months before we start jogging and it seems like if I’m walking and not running that it would be fine.

Thoughts?