Chelated Iron: How soon after last application to getting rid of clover?

Ontario 6a/5b. I had clover take over my yard and I applied Weed be gone via garden hose (2.25% strength) beginning of July and Fiesta (4% strength) via garden hose 4 weeks later to cut back the clover. Amazing results.

Last week of August (August 24) I want to core aerate then overseed the lawn that week. I still have about 20-25% of the clover left. Should I apply another Fiesta spray before the core aeration and overseed or will this additional application stress the living grass that is there now?

My focus is on removing clover, not any other weed. I really don't want to stress the grass that is there at this time so I am unsure if too much chelated iron would do that. And if an application of Fiesta 4% 3 weeks after the last one is too soon.

we get rain once a week. I never have to water the grass even in full sun

I have been applying 27-0-0 slow release nitrogen pellets 3 times this summer with the last application being 3 weeks ago which has helped in addition to the chelated iron.