I suppose that will work. Just remember, you only need a little movement to allow wind spillage once it reaches some level. I don't have any slack in my tarp ridgeline. Because it is a continuous tarp ridgeline with the tarp hanging under it, there is not as strong a push on the tarp as you'd have with a split ridgeline. There will still be "push" - just different dynamics.

My ridgeline is taut and my guylines are kept in shape by about 6-8 inches of shock-cord with the stretch limited by the regular guyline.

For a summer project - once the heat drops below the mid-90s so I can be motivated, I'll play with some theraband. The stretchy rubber exercise tubing. I can see three styles of shock-cord/guyline pairing. Okay, maybe five.

1. Just static guyline - no flex, no accommodation for tarp stretch (like wet SilNylon)
2. Just shock-cord - changes its stretch characteristics in cold temps, not as strong as guyline.
3. A short length of Shock-cord tied to the guyline with the guyline between the two tie points longer than the bungee - that will allow the bungee to stretch but not too far.
4. Shock-cord inside the guyline - Dutch has a video about this - feeding a length shock-cord inside a LashIt guyline.
5. Guyline inside a short length of stretch tubing - that's what I might try.

I imagine keeping the short length of tubing+interior guyline (limits stretch) on the tarp's guyline D-rings and keeping the 4 ft. static guyline separate, attaching it to a loop with a LineLoc that hooks.

I have a couple of tarps and I use a ziploc bag with the maximum number of guylines (plus a couple extra) I'd need. Though it is one more thing to pack (and forget at home or campsite), At this point I like that rather than having to outfit each tarp with its own set. I might change my mind on that later.