Potable Aqua tablets can both sublime iodine vapor and absorb moisture. Soda straws are not impermeable to iodine gas or to water, so over time the tablets are going to degrade. They may look fine, your kit may not be affected much, but they may be inactive. These must be carried in sealed glass or they may not work when needed.

I think you are better off not carrying them than carrying them improperly contained.