If you're running during a regular test and tune night it's not that big a deal. I ran there for years without any problems. They just don't want something obviously wrong, like loose bottle. They don't care about a blow down tube unless the bottle is actually IN the cabin. If it's in the trunk, it needs no blow down tube at all. I never had one and had no issues at all. I've also seen people heat the bottle with torches in the staging lanes.

The only time they are sticklers is during actual sanctioned races. During open test and tune, they don't really check much except obvious things and battery tied down.