If you want precalculated you could do a lookup within Construct, with an array
That'd be much slower due to the overhead of running events. A sin or cos call can usually complete in under 200 cycles, which is about the overhead of running an event that calls an action that does nothing (let alone computing sin or cos).
Yeah, it'll be faster for those who don't care of too much precision.
Actually I doubt there will be any performance gains at all. Since performance improvements in 0.99, sin and cos don't appear as significant CPU users in profiles of the runtime, therefore there is little (read: none) gain to be had from further optimisation here.
Did anyone notice performance improvements in 0.99? They substantially improved the runtime performance, and I don't think anyone mentioned they saw a difference just yet, so I'm not sure anyone would actually notice even if I replaced sin and cos with approximations