Multi-select mass files when smart rending is on

We have a treegrid object, which sometimes can have over couple hundreds even 1000 files on the list. We have dragandrop enabled and have smartrending enabled, not smartxmlParsing though.
Problem is when user sometimes needs to select mass of files by holding shift key. Then we found out, if user jump to the page which hasn’t been rendered yet, shift-select simply wouldn’t work. Be able to select all the files on the list, user needs to scroll whole list of files, then do multi-select, even then, seems there is maximum selection limitation (which is around 300).

Is this known issue? Or we can do different thing to avoid it to make multi-selecting working better?

Thank you,

We have experimental extension which will allow you mass selection in case of smart rendring on. For more information please open ticket at

Thank you, Olga, for responding,

but our support has been expired, can’t submit any case to support. Could you please give me more information here? PLEASE?