The Buxcomm baluns seem to mention "THE core" when describing their 4:1
"current" baluns, and I've had plenty of my responses to my question of
whether or not you can wind a true 4:1 current balun on a single toroid
core.

The answer is no.

I'm sure if you go with the Buxcomm "BIG TALKER" "2500 watt" unit it
won't overheat. It won't ensure equal currents either.

On a marginally related note, why buy when you can build? Better,
easier, and probably cheaper?

Better? Nope, not a real current balun and good luck getting real
technical info out of many vendors.

Easier? Yeah, unless you have to spend months trying to figure out
why, even though you've got a "current" balun keeping the common mode
RF "off" of your feedline, you still get RF bites from your mic.

Probably cheaper? Very possibly true... it is often cheaper to buy an
assembled product than to buy the parts and put one together, but
that's just no fun!

I can't advocate the purchase of simple ham radio station accessories
when someone is trying to build them instead.

73,
Dan
N3OX