Adding ideas to the backlog

In https://github.com/dwyl/app/issues/239#issuecomment-556214589 we discussed that we didn't want to have a backlog jammed with a lot of 'possible' feature ideas or unprioritised feature ideas that we knew were a few months away.

This was because having these in the backlog and in notifications in particular is distracting and adding a low priority label to the issue (such as `priority-5`) doesn't help because this just puts the issue in a black hole ("priority-5 is where issues go to die").

Currently I have a note in my notes app with bullet points of features I would like but are not _imminent_ and I therefore don't want to distract people by adding them to the backlog _now_.

How should we capture these from all members of the team so that they don't get lost?
Would regular backlog grooming as suggested in https://github.com/dwyl/app/issues/239#issuecomment-556214589 be enough to use the lower priority labels and trust the issues won't be forgotten? Shall we have an epic of feature ideas where people can add comments (this seems like the best way to lose information)?

What are everyone's thoughts on process for this?