Hi Tim,

thanks for your report!

The strand option is missing from BLAST interface, but it will be added in the next minor release:
https://ugene.unipro.ru/tracker/browse/UGENE-2396

Unfortunately I am not aware of an easy way to filter annotations by strand. This could be a good improvement for future versions. However one possible option is to sort the annotations by "strand" and then export only those which have direct strand.

First, select one of the blast_result annotations in the Annotation Editor and right-click the qualifier called "source_frame". From the conext menu select option Add 'source_frame' column  (Screenshot 1)

An additional column will appear in the Annotations Editor. Clicking on this column will sort the annotations based on the valuse of the corresponding qualifer: direct or complmenet

Now it is possible to easy select only those annotations which have complement strand (using selection with Shift key) and remove them. (Screenshot 2)

Let me know, if this worked for you.