Not have to, but if you can, do so. Your gear should always be as buff as possible and grinding out the mats you need for that final upgrade is super easy as Rhapsody mentioned. Another way to think about this is, every death buffed equipment prevents is time you save from having to regain lost levels. Some skills take 20 minutes of constant use to get a single level. Things to consider.

Do you have to > no. Will it decrease the odds of you dying when you eff up? Yes.