I think I would try spraying the plant with a water hose to knock off any bugs and cover it with some kind of netting when initially moving it inside. I would cover the entire plant & pot it is in & secure all openings to keep any that weren’t washed off inside the netting. I would also sprinkle a little diatomaceous earth on the soil to keep any bugs from emerging from the soil (a favorite place for them to hide or hibernate). If you see no bugs after a couple of days then remove the netting. If you DO see bugs, then take it back outside and spray again. Most bugs can be knocked off with a good spraying with water. I would also check all leaves, stems/branches for bugs/worms and hand pick those off & smash or feed to chickens.
This is what I do before moving any plants inside or inside my greenhouse for the winter. Seems to work well for me & NO BUGS in the house or greenhouse.
As for the Stevia. I have some seeds to start this next spring. I understand a lot of Stevia seeds do not germinate (for whatever reason) so it is recommended to plant MORE than you wish to have to plant.
Here is some info on how to plant. I didn’t know you do NOT cover the seeds as stated in this article. Hmmm. I’ll let you know how mine turn out after planting this spring. Another article I read said to use FRESH SEEDS and use within 6 months of purchase.
https://www.rareseeds.com/how-to-grow-stevia