Yeah, hierarchical sheets are a great way how to make schematic modular. I use them a lot, however that is what I meant by " if I have the schematic prepared for copy/pasting that particular block". SO basically if you created the blocks somehow and then realize that you would need them differently, then it is not useful.
For example I have and Flash for FPGA configuration. So it goes to FPGA sheet. Then I realize that the memory can be used also for storing some calibration data for the MCU. So now it would be great to have Flash on its own sheet… I either end up with every component on its own sheet or I need to restructure the sheets all the time…
And of course it is only for schematics not for the board. So it will not help me with the issue at all 