ok. Until slickteam get around to adding it you could try using the "filter search results" option in the context menu. If you select slickedit regular expressions, a search string of '[\x80-\xff]|\x00' and choose the "delete line" option, you might be able to remove some of the binary file results. If you add the code below to tbsearch.e then add the commands try_remove_binary and set_binary_filter to _grep_menu_default, they should show up in the context menu in the search results window.
#import "slickc.e"
// the above line has to be at the start of the file
_str def_binary_char_filter = '[\x80-\xff]|\x00';
_command void try_remove_binary() name_info(',')
{
_search_filter(def_binary_char_filter, "IR", false, false);
}
_command void set_binary_filter() name_info(',')
{
set_var('def_binary_char_filter');
}
[Edit] Undo and redo can be used after filtering in the search results window.