This page shows open questions which came up on our mailing list and which we did not tackle, yet. This way we avoid that these issues get forgotten in the mailing list archives.
Windows in the past
Will it be possible to define windows with a scope which lies entirely in the past?
Daniele answers, that windows in the past can be replicated with a query consisting of a DSTREAM window and a normal window here.
Window over window
Will it be possible to create windows over other windows as described here?
Flexible window definitions
Will it be possible to somehow flexibly scope windows as is discussed here?