On the Deluxe plan there are not TS or CS credits, just meal credits. Those credits can be used at either TS or CS/QS places.
The best use of your meal credits is to eat what you want when you want. Don't eat to maximize savings or food for the money. It won't be much fun to eat those 2-3 TS meals with appetizers daily if you're too full to enjoy the rest of your day. If it suits your touring/vacation style to have some CS meals, go for it. No matter how much or little you eat the money is spent, but the memories you create on vacation for last for years to come. One of the perks of the dining plan is not having to worry about menu prices, I certainly don't usually do that when I eat out.
On the Deluxe plan you have a refillable drink mug to manage thirst at the resort and two snack credits each nite, you'll have plenty of food even if you choose some QS meals to keep things light at some point (light for food and for time).
Here is a sample Adult TS/QS day on the Deluxe:
Boma Breakfast $18.99
Casey's Hotdog Lunch $8.68
Coral Reef Dinner $45.46
$77.88 if you add tax to those meals, so even w/o doing all TS or including your two snacks or what you'd save by refilling your mug, the Deluxe plan is a value. You can find less expensive TS breakfast options or more expensive QS lunch options, bottom line you can have value eating QS on the Deluxe plan.