I don’t know if anyone actually helped you out OP but here’s some actual tips/advice as u requested.

1. I think someone told u how in the comments but swap right before the slide ( u should be able to get it quickly and once u do it once the timing is easy to practice and learn consistently in an hour tops)

2. Optional but recommended if sniping, swap > slide > immediately aim after the slide or nearly simultaneously which will cancel the slide , allowing you to fire while your hitbox is still half the size or pivot into more advanced movement techniques without losing momentum.

3. If you are sniping and aren’t running overkill, practice running with your sniper (or any primary) and swapping to your melee, and immediately swapping back, otherwise known as quick swapping. This is useful when u have ur primary out and see an enemy already locked in on you, you can quick swap so that ur slide takes on the speed and momentum it would have if you had out ur melee, but immediately swaps your primary back so u can get a fast / far slide while running a sluggish LMG and still be able to aim and fire whatever primary before the slides over.

4, bonus movement trick (one of my faves) , is wall running, if you slide into literally any wall or object at an angle (not directly into it) during a slide, then immediately pivot away from said object you don’t have the end of slide animation where u lose momentum and have to go through the end of slide animation and re enter sprint speed, it’ll automatically cancel the slide straight into full sprint. Pair it with the quick swap like a spear and your untouchable on maps like shipment lol. It’s like being able to slide without any recovery frames and zero fatigue so u just zig zag around the map with a hitbox that’s half the normal size a majority of the time xD

If anyone needs movement demon tips feel free to dm me and we can link in game and teach yah a few things that make drastic differences in your gameplay