The beta version didn't appear when I typed /proximo test (I tried several times). I can only assume that it's somewhere offscreen due to the new scaling system.
My modified target scripts look quite different:
button:SetAttribute(type, "/target "..name.."\n/script DEFAULT_CHAT_FRAME:AddMessage('Targeting "..name.."')")
elseif option == "focus" then
button:SetAttribute(type, "/target "..name.."\n/focus\n/targetlasttarget")
elseif option == "spell" and spell and spell ~= "" then
button:SetAttribute(type, "/target "..name.."\n/cast "..spell)
The  is essentially a no-op, but somehow it works around a bug in the macro system. Someone on the EU mage forum posted the tip, IIRC. I'm pretty sure I tried [target=name] style targeting too and didn't get it to work, but maybe it would have also needed an extra . My other macros work fine without any tricks like that.
The AddMessage is there just for debugging.