Use Swiftcast manually. It's only one extra button press per minute.

A just Shadow Flare macro is fine, as ground target abilities are the one class of abilities in the game that actually benefit from a speed boost by being macroed.

Trying to sequence actions with waits leaves the door open for things to fail, and doing double-press macros will slow you down significantly. Swiftcast being usable only once per minute, you don't want to waste it on the wrong ability because you didn't execute waits properly, or have it not actually save you any time because you're slowed down by a fiddly macro. The only way to be sure those Swiftcasts count is to do them manually.