PLEASE bring back the PDF thumbnails in X9!!

I have recently upgraded to X9 for Mac OS, and was horrified to discover that the thumbnails of the PDFs have disappeared!  A help-desk query returned with the claim that the thumbnails made the app very slow and the PDFs jump about, but I never experienced that in X8.2!

Thumbnails are the most convenient way to keep one’s place in a document, and in fact they’re about all that make reading a long document anything less than a headache. And in point of fact, having to scroll manually down 20 pages of a document to find your place _has got to be slower _than sliding thru the thumbnails!

Please bring them back!!! Beg, beg…