I totally understand the desire to save money...this is not a spot that I would suggest saving money.
and tap counts and nearly every evening when the wet line freezes the dry line start running. I do have a different environment since I have a brook that runs less then 100' from the sugar house that freezes the mains before the bush freezes.
This happens in many bushes that the low area freezes before the upper warm sections chill for the night.
One could place supports more frequently and have a support that will hold the dry line at a uniform height above the wet line and pull the dry line tight to limit saps; but remember that if there is any sap, then sap will pool in that spot and block vac transfer.
One thing I notice of systems that have more than one main on a support wire is the mains become twisted and pools occur. I am sure this was not a designed occurrence but an issue that just happened.
Weight your options and see if there is another place to save the cost of the wire.
Good Luck!