Tried the double ended lanyard, ran into more problems than it solved, so know I just run two lanyards all the time. Two lanyards is standard up here. Im not quite sure how you would climb most trees safely without it, and by safe I dont mean what you think is safe, I mean the safe work practices we are supposed to employ, not what you feel comfortable doing. Theres a big difference obviously if the OP has been climbing for a while with only one lanyard.
I did that for a few years, in fact when I started, all we were given to climb was and old canvas Asplundh belt, a 2n1, and a LINEMANS POLESTRAP(Im sure some of the oldtimers know exaclty what I mean), so often we had to climb the tree freehand until we could get to a stuitable place to get out polestrap around. One time climbing a nasty old HUGE cotonweed(7-8' DBH) I got my double strap(two straps clipped to one another, real awesome and safe!!!!NOT), caught on a lil stubbie while attempting to get it arounf the girth of the tree, and it was not releasing for nothing.
I was about 30-40 ft up the tree, unsecured of course, and no more gear on the ground to climb up to me(this was 20 yrs ago, we had never even heard of a tree rescue at this point), my older brother freaked and ran a trim truck, literally had to take a run at it, and rammed the truck through a rather deep ditch, close enough to the tree that he was able to get in the bucket and with a four pole pruner, unhook the caught strap. So much fun sitting there holding on to the side of a giant tree for an good hour while we tried to solve the problem. Spurs were sunk right to the iron(punky old softwood bark).
The truck had to be pulled out with a tow truck...lol.
Asplundh footed the bill.
Soon after learned to use my rope for a lanyard with an old steel beaner for a connector, one side just tied into D ring.
It still wasnt at least ten years till I saw my first steel core, I hated them polestraps and still do.