You can if you like :-) Group 2 clems do not always produce a reliable late season bloom. Some are more inclined to do so than others depending on the parentage of that hybrid. A light trim after the first bloom flush (removing only 6-8 inches of the current growth) can help but no guarantees. It really depends on the cultivar.

FWIW, because I have too many clematis to attend to, I hard prune all my group 2 clems. All this does is delay the initial bloom cycle by a few weeks but eliminates the need to track who to prune when and how hard. I simplify it to a "prune" or "no prune" situation. This method does tend to eliminate any later season flowering. But I let my group 3 clems take over that role. 😊