Sequence of tenses (#2)

Dear professional grammar teachers,

Please, please tell me which of the following tenses (present or past) I should use in formal writing in English.  I have been checking many grammar articles about "sequence of tenses (reported speech)" though, I am still confused somehow because I often see many articles in English not following the sequence of tenses.  In my understanding, I believe that I should keep the verb of the subordinate clause "present"
1) when the subordinate clause is talking about a general truth and
2) when the fact stated in the subordinate clause is still in progress (continuing).

Examples:
A) He said that he will continue the research as soon as he returns.
B) He said that he would continue the research as soon as he returned.

In the above B), it follows the sequence of tenses.  However, in A), it is not, and I sometimes see this kind of sentence in newspaper articles. 

Please tell me which of the sentences (case "A" or "B") native speakers would recommend me to use.

In daily speech there is no need to follow the sequence of the tenses especially while u are chatting with somebody.But of coruse if you use it in formal language be careful about the sequence of the sentence.In fact try to be always grammatical

Both sentences are grammatically correct, but they have slightly different meanings. I have changed the 'he' in the example sentence to John to help eliminate confusion in my answer:

A) John said that he will continue the research as soon as he returns.

means that at the time the author wrote the statement, John has definitely not yet returned, but when he does, he will continue the research (at least, that's what John said he would do). The only time this would be correct grammar, is if the author is certain that at the time of writing the statement, John has still not yet returned. If John has definitely returned, or even if its possible that he has returned, then it would be more correct to say:

B) John said that he would continue the research as soon as he returned.

This is a much less specific statement in terms of time, and allows for the situation that John has already returned, that he hasn't yet returned, or that he may have returned without the author's knowledge at the time the author writes the sentence. If John has returned, then presumably he is either continuing the research already, or he has broken his word.

Thank you for all your comments and advice.
You have helped me a lot in deeping the understanding on this matter.