not really, just think of an exchange, they have many more transactions than the Bitcoin blockchain can process, they have there own servers and internal accounting system (it could there own PoS coin or somthing like the NASDAQ) all OT does is ensure that your balance is locked and released when cretin criteria are met with a N of M script your bitcoin can be moved.

in this application it is similar or indistinguishable from a decentralized exchange using SC.

An alternate currency for example - with OT would be a for profit company - say for example a micro transaction currency, what OT would provide is a trust free way to secure your BTC, there internal servers or blockchain ledger would manage the system - risk, demand and competition would keep scales appropriate, and there dev team could trim the block chain as needed. if there micro payment coin was in high demand there would be an exchange rate floated either on the market or set by the company.    

but the above example with a SC would run at the prototypical level, and be totally decentralized the design of the coin would most likely be merged mined to incentivise mining, over time it will generate more revenue for miners than Bitcoin, the result is there is a motivation to mine and secure the SC's as they grow, the Bitcoin chain can be MM but if it gets to a point where it docent generate enough revenue because the revenue is generated on the SC, it will leave bitcoin vulnerable to exploration or attack.

this is the trade off with SC, the trade off with OT is market competition, you have to earn you way to the top, you cant boot strap you way up by getting something for nothing (mining) and risking Bitcoins incentive sachem.  



to be taken in context with the previous discussion, if the SC is more valuable it is a reason not to transfer back.