In the second load-out by Add to my bag the ring (Stichflesh’s Mispladed Signet M+15 plus socket) has an upgrade value of +2%+:
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If moving the secondary load-out to the fist place the ring will be ranked correct as -0.1%:
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Plus a feature to tell Mr. Robot to add sockets as default would be nice.
I think that the ranking is working correctly here. When your Balance M+ setup is second, all of the modifications (gems, enchants) are being “reserved” by your higher-priority Raid setup. Thus, getting another ring that the optimizer is free to put whatever gem and enchant it wants onto it scores higher.
When you move the M+ setup to the top, there are no restrictions on what gems/enchants can be chosen on any of your items. In that case, getting another ring isn’t as valuable.