Like I said, debuffs work based on the opponent turns. Damage over time is subtracted at the end of every opponent turn, and so is any damage that opponent does to your dino. So if that opponent kills your dino with its last attack, the damage over time happens simultaneously, as much a part of the turn as the damage it deals to you.
The whole point of auto swap-in is that it’s not a separate turn. Manual swap-in, being an action is a turn.
SIA is a turn, being an action, like I said above. If you intercept a swap-in ability with a faster creature that has SI-stun, that creature will get stunned only for its SIA turn, not an actual playable turn. This is what I tried to explain above.
I did state that swap-ins are not counted as turns for creatures without an SIA, that was a mistake.
As for my claim that any action, including an SIA, is counted as a turn, it seems to fit every single situation I’ve come across. All confusions regarding how long abilities and debuffs should last seem to stem from the misconception that a turn is a complete interaction between two dinos.