Based on the previous suggestion of mine as well which was tagged as a feature request by Leia as well but not sure at what stage it is right now. So re-posting this as a feature request.
I am not an FBA/FBM seller but I know there is a keyword field where you can enter quite a few keywords for which you would show up in search results without having them in place in title or list/bullet points. This is one area which I find is lacking in Merch by Amazon.
We see also complaints from many every now and then about how people are keyword spamming the bullet lists. I believe if there was a keyword input field like Sellers Central, these group of people would be actually compelled to write a nice sentence instead.
And there's only so many sentences one can form without looking unnatural. If there was a keyword input field, we could enter a lot of untapped/potential keywords as one cannot fit enough of them in natural sentence and also considering the character count limit.
So this is a suggestion for it. Help us have a search keywords field where we could enter them and be founded if someone searches for it.