Hello everyone,

I'd like to ask about the proper tense sequence in the sentences introduced by the verb "recommend", as in the following examples:

1."So it was recommended to wait until equilibrium has been established."

2. "They recommended waiting until I return."

3. "My son's pediatrician recommended to wait until he is 2 or 3 before seeing an allergist."

I often see similar cases where the verb introducing some sentence is in the past tense but the verb in the dependent clause doesn't agree in the tense with it. That is, I would expect "was established" in the first sentence above, "returned" in the second sentence and "was" in the third sentence instead of the verbs in present tenses used in these sentences.
I wonder if the use of the verbs in present tenses in the above sentence can be explained by the fact that the actions in the clauses after "until" are still actual, i.e they haven't occured yet, and since the present tense of the verb is used. For example, "is" in the third sentence is to be explained by the fact that "son" haven't turned 2 or 3 years yet, and using "was" would have situated the entire context in the past and would have meant that he's older than three now?

Thank you for the help