here's how the distribution works: extra filter surface area isn't needed in reefing its just something random 100,000 people do, its a carry over habit from freshwater keeping. without it, your reefing params run the same as with it, its neutral.
your rocks and sand are the primary action zone.
so if your filter was on the whole time, it'd pick up bac in excess of what the system needs to run.
and if it was off, that doesn't matter as filters aren't needed in saltwater. See how that works
and then when you turn the filter on, the water circulates between the uncycled filter and the cycled main tank, and the filter is now cycled in three days just the same.
the helpful thing your filter does is move water.
if you ran it totally empty, you'll have the same reefing parameters as if you ran it packed with various high surface area media. some choose to put phosphate controlling media in them, but that's unrelated to cycling. they're not needed in that regard.
just in case I didn't make the case well enough about filter neutrality in reefing, take any reef tank on this entire forum. We can remove its whole sandbed at once, and all the filtration surface area they use in a sump. Gone, immediately, leaving only the live rocks and the same fish.
It all works the same. no cycle...we have a fifty page thread already doing exactly this work. It will help you to know ahead of time your filter isn't some integral link to the reef's life, its merely a water pump mover.
this means you are free to cycle how you want
or hook up and try any other device, they're all expendable. your live rocks are the core source of heartbeat, we keep those safe in our work threads while robbing all the other areas to be cleaned or just made tidier and changed to bare bottom etc.