Would be nice if you could really customize the slide-nav links in slider components (similar to the way you currently have the ability to edit or add elements in the slide arrow blocks). For example, if each link was a link block element that you could replace the "dot" in it with an image, text, or whatever you wanted. This would make it possible to create clickable thumbnails for each slide in a slider without having to use custom code or javascript.
Also being able to change the color of the arrows and pagination based on the visible slide. Some slides are dark, some are light. Keeping them visible regardless of any slide's back ground would be excellent.
I can't believe that this has not been done yet... it's such a pain to get the slider nav in line with your site at the moment... using custom css should not be how Webflow is supposed to work... hope this feature will be added soon.