Can lights should actually be supported by the ceiling grid. Installing canned lighting with Ceilume tiles isn't an issue. Here's a link to Ceilume's information on lighting. Take a look at the video within the Recessed Lighting section - this should answer all of your questions. If not, let me know and I can clarify.

https://www.ceilume.com/lighting.cfm

Please let me know if you have any additional questions.

Thanks!
Amy