Spin-up height limit clarification

Just had a question about Spin Up’s SG5 rule.

For the limit on vertical expansion, are you only allowed one part that extends above 18” that fits into the 2” diameter cylinder, or are you allowed multiple? Are you allowed to have multiple parts that do it but only one extends at once during a match?



SG5 is mostly to prevent blocking and dumping discs into high goals. It seems to me that as long as there is no extension that is bigger than a 2" cylinder at any one time you are good. If you have 2 things that poke up, they can’t all poke up at the same time but can poke up individually.