I have a feeling that they are etymologically related based on their kanjis 兎も角 and 兎に角 (although they're just 当て字 so there's not much to extract from those kanjis, I guess), but I can't fully understand the explanation in here:
とにかくは、他にたくさんの些細なことがあっても、目下集中すべきことを優先する場合に使います。 用例)水泳には筋トレなど、たくさんの練習方法はあるが、とにかく泳ぐ。
ともかくは、他に優先すべきことがあるが、それを差し置いて優先する場合に使います。 用例)試験勉強はさておき、ともかく泳ぐ。
Does it mean that in とにかく there's an implication that the other things are 些細 or trivial while in ともかく it doesn't "trivialize" the other things? Also, do you agree with this answer?