If my already-poisoned Pokemon is hit by Dragalge's "Poison Cultivation" attack then I use Switch while Dust Island is in play, is my new Active Pokemon poisoned with a regular condition (only one damage counter in between turns) or with the effect from "Poison Cultivation" (ten damage counters in between turns)?

If the Poison effect places more than one damage counter during the Pokémon Checkup phase between turns, then switching the Pokémon out using a Trainer card while Dust Island is in play will retain the modified Poison effect of placing multiple damage counters on the new Active Pokémon.

Relevant cards

SM10_168

SM12_92