My grammar book says the もいいですか is used with verbs, adjectives, and noun+copula. But will something like this be understood?
With the omitted verb (行って) being understood from context somehow.
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I think we cannot understand it from context somehow.
If I heard the sentence "東京へもいいですか", I would think that you wanted to say "東京でもいいですか" or "東京もいいですか" because we never say "東京へもいいですか".
For example, if you plan to go to 大阪 and your boss knew that you are going to go to 大阪. You want to go 東京 too, but you need your boss's permission.
Even in this case, we don't omit "行って".
However, It is a rare case, but you could say "東京にも（へも）・・・いいでしょうか。".
You can say this in case your boss knows you want to go to "東京", and you know that he/she wouldn't allow you to go, but you want to give it a try.
You also can say "東京にも・・・・・・" in this case.
But, I think this is a rare case and it needs "・・・".