On smartphone, the left sidebar has a dedicated menu button in the upper-left corner. However, the right sidebar has no button, and can only be accessed via swipe.
For less tech-savvy users, this essentially renders the right hand sidebar non-existent to them unless they already knew about it. Or worse, they could become confused or upset if they accidentally open it and it unexpectedly opens without them knowing it would.
I would potentially suggest either adding a button to open the right sidebar (like on tablet/desktop), or merge the contents of the right sidebar into the left sidebar on smartphones specifically. Thanks.
I understand this is probably a compromise to make everything fit in the top area, but I think having no visible control for a major part of the interface is a bad idea. I’ve seen questions from people who don’t know it’s there. And I totally forgot about the long-press — probably because it’s surprising, plus swiping feels faster to me (there probably isn’t much time difference).