Risky Business
Gotta say.... I have never seen an Ericson from that series (32-3, 35-3, 38-xxx) with single lowers.
Those forward lowers have important work to do to keep the mast column from inverting, and the aft lowers keep it from pumping, also.
OTOH, I must admit that my Olson (same builder but different designer) has single lowers AND running backstays. In seas large enough to cause the boat to slam into crests at all, this system requires setting up the runners to control pumping.
Of course in the more protected waters of our river we do not use them.
Since your particular spar was spec'd out for the rig it has, I would not change/weaken it. If you modify the rig and it pretzels, expect your insurance company to reject that 15K claim in a heartbeat, too.
I betcha Seth or Martin or any other ex-factory guys or riggers here will have some far-more-educated comments on this, anyhow.
Loren