I've never had a chameleon go on a hunger strike, because I offer variety all the time. Some weeks my chams may see more crickets a lot and then not at all for another one, because I also feed superworms, butterworms, hornworms, silkworms, 3 types of roaches, and sometimes wild caught insects from a safe location. So the average is about 3 different species of insects a week, if not more.
You can still offer variety, just not really mealworms. I don't think they're as awful as their reputation on this forum makes them sound, but they are sort of measly nutritionally. So if you can get your hands on any other feeder (like the kinds I mentioned) those would be better choices.
Also, veileds sometimes will eat veggies and fruit. Any fruit/veggie that is safe for gutloading is safe for feeding directly, like little slices of dark greens or strawberry, for example. You may have to wiggle them between your fingers to make them look alive though, chams take a little to recognize veggies as food.
Edited to add to Skybound's question: No, not really. No one insect should make up 80-90% of the diet, you need diversity to get really good nutrition. Many insects can be bred at home so it's cheaper, so it's easy to have at least 2-3 bugs breeding at home. Crickets actually have a really poor phosphorous to calcium ratio, which is why it's so important to supplement with calcium so the ratio is more even. So they're not excellent feeders, they're just easy to use. They're great as part of a varied diet. And this is especially easy/affordable with one or two chameleons, I think.