Most abilities can be used while reloading and have no effect on the progress. There are several that do not behave this way, mostly cancelling the reload action completely: Billy Bashdown, Dynamo Singularity, Haze Bullet Dance, McGinnis Spectral Barrage, Pocket Enchanter's Satchel, Seven Ball...
If weapon damage is reduced to -100% through debuffs then most bullet based effects stop entirely. Exceptions being Mirage Djinn mark if there is no present debuff, Wraith Full-auto, Mercurial Magnum, and flat bullet(not spirit) damage buffs.
Unlikely but possible with Graves and Warden in...
The attachment hitbox for Lash Death Slam is very finnicky when even slightly below the target. All of these images are examples where it looks like the target is in clear line of sight but will not be grabbed. It's as if the line of sight requires the very bottom of the model to work.
Vyper's Slither tooltips have broken elements.
In the spirit tab, the barrier always shows 0
The cooldown element is only visible the one time it is upgraded while the tooltip is pulled up. It does not include cooldown reduction modifiers.
Timestop effect from Carbine behaves oddly with channelled abilities. For dynamo's Singularity, the effect of black hole is extended while the channel time is not. This allows dynamo to move for about a second after the channel 'finishes'
The Freeze effect from Arctic Blast and Frostbite Charm does not stop movement like other immobilises. Momentum, dashes and slides are all allowed to continue with no loss of speed.
Sinclair's Spectral Assistant placement is not counted as a movement ability and is not silenced by slowing hex. Immobilises do silence the placement. This is unlike Pocket Flying Cloak where only the teleportation action is silenced.
If Lash uses ground strike on an enemy that in air but close to the ground, they will be stunned and stuck to lash for a few seconds as if he was dragging them down mid-air. This can be abused with echo shard to knock-up the target to correct height before using again to kidnap.