During pregame count down, I hit knife and sprint, (toggle) and I don’t press it again until I have to.
Seems to me that it would make more sense having sprint on be default and press to walk.
Without a stamina system anyway.
at least I remember thinking that, seems daft but can’t get in game to see.
Yeah but once you’ve toggled it on it turns off and on again on its own, doesn’t it?
Well if you like that just have toggle sprint on. I personally hated the way toggle sprint works in this game where it will turn sprint on always. Usually with toggle sprint it’ll toggle off when you stop moving or do an action.
If you could shoot and reload while sprinting then there wouldn’t be a reason to have sprint, and you’d instead have a walk mode, like in CS. But since it does prevent you from shooting and reloading, it does have a place here. Sure you do stop sprinting when you start shooting, but there is a significant delay there for your character to bring up the weapon. And if your character stops sprinting to reload, what if you wanted to cancel the reload to start sprinting again if there was no sprint button?
Since there is quite a delay between stopping sprint and drawing weapons/interacting with objectives, holding a sprint button seems to me the best way to manage sprint nicely. If you want to have good reaction times it’s sometimes advisable to stop sprinting before action arrives on you. More or less like pre-shooting in some games. In a sense, sprinting management feels very similar to me as urban-terror did : there you have stamina but you can shoot even while sprinting but with a noticeable precision penalty. Sprint management is to me something where skill improvements can sometimes be made.
I didn’t notice any delay, I’m pretty sure I was testing whether or not to use toggle and saw no drawbacks to using it so I left it on.
I think I only had to turn it back on after dying.
I usually manually sprint too, if theres stamina or something. But seeing as I could sprint without drawback I thought I’d save the finger ache, as I used it alot.
And with regards to reloading whilst sprinting, you just turn off/on the sprinting cancels reload option. That solved any issues I had at least.
I have to agree with the finger ache 
I used to press shift for sprinting but I have noticed that I have usually spirint always on. Thats why I have switched to toggle. This has left me wondering point of sprinting, if there is not any kind on stamina, then in my opinion sprint should be always on.
Leaving it on toggle should be fine. Having it always on will mess up gameplay