Homecomin you should be good walking up for a table, especially if you go at a more off time. We've never waited more than 20 minutes if we go between 2pm and 5ish.
We've used Touring Plans reservation finder many times and have had great luck getting Topolino's for breakfast and dinner, Beaches & Cream, Be Our Guest among others. Just make sure you click the link ASAP! I've also had luck checking for reservations the week of or day or two before we'd like to eat somewhere because people are cancelling reservations so they don't get charged. I've also seen Topolino's and SciFi show up on the walk up waitlists on the app so keep an eye on those on the day-of if you still weren't able to snag an ADR.