Let me see if I can put something into a coherent explanation....

I find when I merge the linked layers while I am on an active layer set at NORMAL blending mode, the blending appearance does not alter upon merging the layers. And its better to link your layers and then merge them, rather than simply merging down.

Er...usually, anyway. Don't bet your life on it ;)

Obviously in hindsight it would have been better to Liquify, then duplicate, then apply blending effects.