Why 言ってます instead of 言います in 昔の自分に会えたら、言ってますよ?

Question

けど、昔の自分に会えたら、言ってますよ。そんな悪い癖染み付く前にとっととやめろって。

I am not sure why 言っている is used rather than 言う. I would expect する after the conditional, e.g.「友達に会えれば、買い物に行きます。」(Tae Kim)

I would've used these:

昔の自分に会えたら、言いますよ

昔の自分に会えたら、言ってやりたいですよ。

昔の自分に会えたら、言ってやりますよ。

Most examples I have been able to find online use する:

過去の自分に会えたら、なんて伝える

いまあのときの自分に会えたらどうしますか？

I only found one instance with している

いつかお兄さんに会えたら話せるように韓国語を頑張って勉強してるんです！(source)

This is the second aspect question I have asked in recent weeks, and it seems to be a different issue from this.

Answer 1

This condition 昔の自分に会えたら is an unreal one. The ている form is used to describe a current state you would be in if that condition were satisfied, rather than an action you would take then.

If I were able to meet the old me, I would have (by now) told him to stop a vice like that before it became a habit.

All your three sentences are perfectly fine.

Your last example is different. It simply describes what the speaker is doing now for when some event happens in the future.

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[EDIT]

An alternative interpretation is this ている form describes a continuous action.

If I were able to meet the old me, I would be (constantly) telling him to stop a vice like that before it became a habit.