I have a doubt regarding the tense of the verbs in the ついでに grammar pattern for the two clauses. Consider the following sentences- 一時帰国したついでに、アメリカでは買えない物を買います。 N3のテキストを買うついでに、漫画も買ってしまった。
I saw a rule in a video that the tense of the verbs in both the clauses must align with each other. For example, you cannot say 大阪へ遊びに行ったついで、今晩京都へ行きます。This is because the first clause is in the past tense and the second clause is in the future tense. So the correct sentence must be-大阪へ遊びに行ったついで、京都も行きます。 Can someone explain me why this does not apply to the above two sentences and the logic behind that?