What does 論 mean in 時情天意枉論量？ The meaning of 論, when pronunced as lún, has already been listed in the answer by @user-487 in another question. However, none of those meaning seems appropriate in the following famous 朝中措 by 元好問：  


  時情天意枉論量，樂事苦相忘。……


“通‘倫’，事物的條理、秩序” sounds acceptable, but still makes me feel strange. Is there any reliable sources that clarify the meaning of 論 here?
論量/论量 ㄌㄨㄣˋ ㄌㄧㄤˊ/ lùn liáng

依《漢語大詞典》，有二義：


評論、計較。
　唐吳兢《貞觀政要‧論任賢》：“至於論量人物，直道而言。”
　金元好問《論詩》詩之三十：“撼樹蚍蜉自覺狂，書生技癢愛論量。” 
猶思量。
　元袁桷《睡覺東西書燈猶明喜勉元達兼示瑾子》詩：“師友淵源端有緒，老夫推枕起論量。”


此處“枉論量”是指“沒什麼好談論計較的”。枉, 白費 (useless)；論，談論 (to talk about, to argue)；量，較量 (to compete with)。

根據《康熙字典》：論
《玉篇》力困切，《廣韻》《集韻》《韻會》《正韻》盧困切；同崘，去聲，義同。
所以，古時即有去聲。