First, the Second Comforter means a visit or personal appearance to someone by Christ. However, the appearance is not as important as the ministry of the Lord. He "comforts" those to whom He appears. He will "not leave you comfortless, he will come to you." (John 14: 18.) Christ and His Father will "make their abode with you." (John 14: 23.) Meaning that the Son will bring you to the Father, and the Father will receive you as His son. This appearance is not merely "in the heart," but is an actual appearance or visit. (D&C 130: 3.)
However, the purpose of the ministry, the reason for the "abode" with you, the "comfort" that is promised by the Lord, involves the promise of eternal life. The promise of eternal life has been made an equivalency by the Lord in a revelation given in modern times. That is, the end or result of the ministry of Christ as the Second Comforter is to have the promise of eternal life. In a modern revelation the word of the Lord was given to a group of Latter-day Saints in which the promise of their exaltation was extended to them, and the Lord made this the equivalent to "another Comforter."
Here is what was said:
"Wherefore, I now send upon you another Comforter, even upon you my friends, that it may abide in your hearts, even the Holy Spirit of promise; which other Comforter is the same that I promised unto my disciples, as is recorded in the testimony of John. This Comforter is the promise which I give unto you of eternal life, even the glory of the celestial kingdom; Which glory is that of the church of the Firstborn, even of God, the holiest of all, through Jesus Christ his Son— ." (D&C 88: 3-5.)
Therefore, as a singular appearance, should the Lord appear to you, you have received the Second Comforter. However, His ministry is to bring you to the point at which you can receive the promise of eternal life, membership in the Church of the Firstborn, and the promise of the Celestial Kingdom as your eternal inheritance. In the fullest sense, therefore, the final promise of exaltation in the Celestial Kingdom can also be called the Second Comforter, since that is the result of His taking up His abode with you.
The second concept is really a question: Would it be preferable to have the promise of eternal life now than to die uncertain as to your eternal state? If so, then why would you waste your life now in hopes that some other opportunity may exist at some other stage?
If the answer to these questions are "yes" then the original question is simply unimportant. Why wait? The opportunity given to you now should not be forfeited, nor should the work be delayed. Don't dismiss the Lord's offered assistance for what you can achieve in mortality for the possibility of something in the after-life.