We have two-line reefing all led back to cockpit with halyrd back too; works fine. Did convert it to single line but yards of string & friction & slow so changed back to 2-line.....
What size of line r u using? 5mm ?? should be able to whip 2 of those into a 10mm sheath - planning on trying this method with one of our reefs as we have the single line atm (without boom blocks) and it could be smoother!
I've got the original reefing line on the leach which I think, without mesauring it, is about 8mm, and then a 6mm line on the luff....
Clutches will take up to 12mm, but seem to accept two lines of these sizes quite readily... although I can't get a single 14mm line through!
Only downside is that you do have to be careful about positioning the lines in the clutch otherwise the smaller one will slip... so not ideal in the long run, as it would be bound to slip when you needed it most, so I am going to add a small jammer for the luff line rather than splice them, (I think a jammer will be fine as there is no problem in getting the line tight when the halyard is loosened, unlike the leach line which needs winching down) as I have found that for the 2nd and 3rd reef you are way past the splice, and the two lines would end up in the jammer anyway..... maybe fine with two identical sized lines, but not sure 5mm would be strong enough for the reefing lines.... and big clutches are really expensive!