Top down furler, length & tension question.

[[3889]]

I've bought a Seldén GTX TDF for my asymmetric. Before I cut the 16m anti-torsion cable I'd appreciate some feedback on options. The sail luff is 13.2 m so there is plenty of spare capacity to accomodate it on the 15.2m sprit to halyard-sheave length, even accounting for clearing the guard rail. Is there any reason not to control the luff tension via the halyard whilst flying the sail? I dont have an available lead to run the tack line to a winch and would prefer to avoid the expense of installing one. I appreciate that the luff needs to be fully taught whilst furling and unfurling.
I've also been advised that I should replace my Liros Herkules spinny halyard with cruising dyneema. Is this necessary for cruising?
I don't race so no worries about delays in launching / furling the sail whilst tensioning the halyard.

 

[Tranona]

I had no problems with tension on mine just using the standard braid on braid halyard, but a bit shorter than yours and probably smaller at around 65 sqm. Best bit of kit was the Selden stanchion blocks and double jammer for controlling the furling line.

 

[yoda]

Have a read here: https://support.seldenmast.com/files/597-200-E.pdf
Right at the end of the document there is reference to an anti-twist shackle, this is easily fabricated using a stainless rod and cutting a thread onto it. I found this a great help in reducing the necessary tension. I would start by making the torsion line to the longest possible length and trying luff adjustment with the halyard. Ultimately the real answer is one of the adjustable tack fittings but just more money!