Normally I write quite a lot of comments each week. Which results in a few comments getting upvoted. And an even smaller number of these comments gets an upvote below the so called $0.02 dust threshold.

This $0.02 dust threshold means that each upvote value below $0.02 will te result in a pay out.

Is there any good reason to upvote comments if your upvote value is below $0.02?

NO, at least that's my opinion.

You could say that one shows his/her appreciation to the commenter. And that could be a valid reason. However, to my opinion that results in your upvote getting lost and making the rich even richer.

Any solutions?

Don't upvote comments if you currently (26th of August) have less than 400-450 SP.

I think the most easiest solution is to upvote a recent post from the commenter. With recent I mean not older than 7 days.

Another great solution is to buy a Hive account@dustsweeper subscription. This automated account makes sure that all your dust will get an additional upvote to increase the value above $0.02. This will solve your own personal dust issue. But of course not that from other Steemonians that you upvote.

What will happen to this $0.02 dust threshold after HF20?

I don't know.
Does anyone know this by heart?