using a jumper cable - connect which set of post?

IMHO, it doesn't matter. I usually use the lowest set of posts, so it puts less strain on the cables.

My speaker manufacturer did express a preference for connection, but I couldn't hear any significant differences. I also opted for the lower posts as a matter of better cable ergonomics.

I always preferred the low-frequency posts for the direct connection. The bass was muddier the other way. This happened both times I had speakers with jumpers.

Try it, see which way you like best.
I am of the opinion that most info comes out of the tweeters, so the connection should go there

As can already be seen in this thread, opinions on this question will inevitably be diverse. Some people say to use the low frequency posts, some say to use the high frequency posts, some say it doesn't matter, and in past threads you will find some recommending connecting one conductor to the low frequency post and the other conductor to the high frequency post.

IMO, assuming that contact integrity is good and that the jumpers are reasonably short and of reasonable quality, whatever differences may be reported are neither technically explainable nor technically predictable.

Regards,
-- Al