I typically have two blocks on the toe rail track and one on the inner track.
When Iíve flown a symmetrical chute with separate sheets and guys the guys are led to the rail.
This gives a better lead angle for more down force on the pole. It also lets you crank in both guys with the pole off to stabilize the chute while jibing in heavy breeze.
The other toe rail block is used for a jib sheet hooked on for reaching. This allows the lead to be outboard
and forward for more power.
The car (block) on the inner track is mostly for upwind.
A second block in any case makes flying headsail changes easier while racing
Say you are on starboard tack. The jib is in the port luff groove. Put the new jib in the starboard luff groove with the new jib sheet led to the second block on the starboard side. Hoist the new jib inside the old jib. Tack and trim in the new jib. Now drop the old jib on deck
inside the new jib. Move the lazy sheet and you are all set.
If by chance you find you must tack while in the middle of all this (two jibs, one halfway up) you will be on port tack with sheets for both the inside and outside jibs. So no troubles.
I have found that many of the maneuvers and skills I learned from full crew racing
are valuable while short handed cruising. Just take your time.