Should I have root canal treatment if it's not bothering me daily?

I had root canal on a tooth over a decade ago now and since then all has been well until now.

I noticed a cyst on the gum above said tooth a few months back and the NHS dentist referred me to a dentist "with special training in Endodontics" (I'm UK based) to do the root canal again.

The cyst doesn't bother me at all. I can eat normally etc, and only notice it if I physically touch it.

My question is, should I get it done with a specialist now or should I wait until it really becomes a pain?