Gents, thanks for any help in advance

I am just about to make a 20mtr delta loop using 72foot wire, 4.1 balun, fed by coax.

I am going to use this antenna for DX and install as a three sided triangle (pyramid) with the apex at the top as that avoids having to use fibreglass poles to support the side legs if set up as inverted triangle. I am going to use a 40foot telescopic mast to support the top apex and tie the two bottom corners 12 foot off the ground, so the bottom horizontal section will be about 12 feet from the ground and obviously each section will be 24 foot long.

A couple of questions:

1) is it better to install as an inverted triangle for DX ?

2) where is the best point in the triangle to locate the balun as I am aware this quite drastically changes the antenna ?

Thanks for your help

73s Simon