I got a new membrane, some DI resin, a 32 gallon trashcan, and a handheld TDS meter. Inside the trashcan, there is a strong odor of the plastic they used to manufacture it. I rinsed it out real good, and also let it sit with water for about an hour. Tap TDS was about 160, and after the hour, I tested the trashcan water and it was 160, so I am assuming there is no leeching. I did a search, and someone said to just monitor any leeching with the TDS, but I was wondering if it is confirmed that the TDS meter will detect plastic (or whatever chemical may leech). I believe that the TDS detects conductive ions?... but I'm not sure if the plastics, or similar material used, would fall under that category.
I did make some RODI water in the trashcan, and its TDS was 0ppm. Several hours later, still 0ppm. I've got salt mixing in it right now (not used to my filter making water so fast!), so I hope it's going to be OK to use. I'm just worried and am looking for confirmation that it should be safe. There weren't any sustained bubbles, film on the surface, and when the water is removed from trashcan, it does not have the odor.
Also, I usually just have the membrane flush on for maybe a minute before I make some water, but my LFS said that it should be on the entire time. Is this true?

Thanks a lot for any help.

No, the membrane flush should not be on the whole time.

Do you know what the trascan is made of? It should be stamped somewhere (probably on the bottom). It will say somthing like PETE, or PE or PP, or somthing similar. It's likely PETE (Polyethylene terephthalate) which is food safe and should be just fine. A slight odor is perfectly normal, it's volatile organics from the manufacturing process "off gassing" and shouldn't leach into the water. If the smell is strong, or it bothers you, just stick it outside for a day or two (empty of water) where it can be exposed to the sun and wind. As long as the TDS meter shows zero (or no increase from whatever your RO/DI is putting out) you should be fine.

I may also recommend washing out the can with a baking soda and water solution. I do this with all containers I want to be assured are clean for water. Always try to buy food grade safe containers if possible.