I would not expect any change in SeleniumLibrary to handle these dialogues as it is just a wrapper around the core Selenium Webdriver code, and given the number of issues people have getting Selenium Webdriver code to work with these dialogues and the number of issues as it keeps breaking in various releases of Selenium Webdriver.
I found this article which appears the be for Selenium Webdriver Java Code:
Note even there option 2 is use Autoit
I also found this issue:
The post on the 5th May 2015 has links to various methods of getting it to work.
Obviously with these links you will need to figure out how to translate those suggestions to the RF keywords, the theory being it should be possible, but it looks like it’s never going to be reliably easy in Selenium.
What impressed me with BrowserLibrary was that they supported in the first version getting the http response codes (when a server returns http 404, 500 etc) which the Selenium developers have refused to do for many years (I have seen several issues raised on this were closed as won’t be supported), for me this is enough reason to migrate to BrowserLibrary.
Dave.