John Forrest Tomlinson writes:

What happens if fitted with the heart "upside down"? I checked my
two bikes with Connex links and I see one is right side up and the
other upside down. I never noticed any difference in how they rode
or shifted.

Supposedly it doesn't work so well on very small cogs.

Don't do that! What do you mean by "supposedly" and how is that
caused. This is not religion class. We can't rely on the
infallibility of the Pope here. "Let's get to the facks ma'am, just
the facks", as Sgt. Friday would say.

Jobst Brandt