Can I seal taillight completely?

Hi, I got new aftermarket taillight. I did seal between housing and glass, but I noticed large holes at behind. I sealed most of them, but can I do complete seal and block all holes from behind? Is it safe? Or must keep small hole to prevent heat? Some say you can, others not, what is your opinion?
I uploaded pic of taillight and the holes which I did block most of them and want know to continue block the rest or not.
Thanks