I'm not a Mac user, but having used dd a lot in Linux, here's what I can offer. The different size shouldn't be a problem since the source is smaller than the destination. You'll end up with a partition table that doesn't know about the extra space, but you can change that later with gparted or other partition table editor. I don't know about the filesystem, but in Linux, ext4 or xfs can be expanded into resized partitions that have been expanded easily.
On the sector size issue, I don't think it will be a problem for the data copy, read 8x 512b sectors to write 1x 4k sector should be ok. The problem will be the boot sector, which at some point in the bootstrap must find something via LBA and that is likely to break. In Linux land it's not hard to rebuild the bootsect from a recovery CD or USB drive, idk about Mac but I would assume there is a procedure for it.