I'd like to be able to grab a substring from right to left. Currently this is only possible to read a substring from left to right. A single dash, -, can specify the end of a string, or length of a string. A negative one, -1, can be used to specify the first character at the end of a string, and so forth. A negative string length could grab from right to left.
example.
%ss(-,-3,%it) # read the last 3 characters in the title tag
Also I'd like to be able to specify the amount of time to display a viewport after keypress. Similar to the %mv(t) option which does something for t amount of time when the volume is changed. Ultimately I'd like to display a viewport for a specified amount of time during and after playing, pausing, fast forwarding, rewinding, or placing the player on hold.