you are completely correct about check blocks typical application but this unit looks like it could easily be used with a dynema strap and hung anywhere and states it comes with a "Shackle/Strap Type: UV-stabilized, multi-strand Dyneema rope link"
the downside to using this as a regular turning block would be the ratchet on/off switch would be upside down on one side of the boat (and may not sit flush like the other side would) - wouldn't bother me unless it scratched up my boat
Great find... never thought I'd see "good deal" and "west marine" in the same sentence... they are undeniably conveniently located for me, but rarely very affordable.
I use the non-cheek version of this as my jib blocks on my H18, with the addition of a becket and cleat, and they work really well.