I might be able to help you, but I need you to clarify exactly what you mean on a few points.

1. I'm not sure what you mean by "up to good". On the 18th of April, as Carpathia headed for New York, the Navy intercepted wireless messages from Bruce Ismay indicated that he was intending to return to England. The word "intercepted", to us, may indicate something covert or secret but it really wasn't. It was transmitted by radio and would have been picked up by any ship in the vicinity. There was no way to send a "secret" message to anyone via wireless in 1912 (at least not that I'm aware of). Intercepting messages was how the press received news during Carpathia's return. Messages transmitted would be picked up by surrounding ships and then passed on. The US Navy was in the vicinity, they heard Ismay's message, and relayed it. They also would have heard every message.

They passed this information to William Smith because they knew the Committee of Commerce had been granted the right to an investigation. Smith had to clear that it was possible to subpoena a non American- which AG George Wickersham said was fine as long as they were on American soil. Smith, his staff, Senator Francis Newlands and US Steamship Inspector George Uhler greeted Carpathia at Pier 54 and subpoenaed Ismay.

But let's be clear, Ismay wasn't trying to sneak out and had no issue with the subpoena. He simply wanted to go home, and had little- if any- knowledge the US Senate was forming a disaster investigation committee. He was a British citizen who simply was making return travel arrangements.

(A caveat- I may be wrong here. Ismay stayed in his cabin the entire trip back so we don't really have a lot of information as to his motives, ulterior or otherwise. He was branded with the patina of a coward and villain post-Titanic, and it's very likely this idea that he was trying to sneak away was an offshoot of that. I'm simply saying, we don't actually know his motive- all we know is he wanted to go home).

We have his opening testimony to the fact here and also referencing my caveat, which I'll quote-

I know that my personal conduct has been made the subject of a lot of unfavorable comment, and I court the fullest inquiry at the hands of your committee or any one else who has the right to ask such questions. So far as the Carpathia is concerned, when I got aboard that vessel I was taken to the saloon and a steward wanted me to eat some soup, but I could not. He then led me to a room and made me comfortable. The room was never locked and was frequently entered. The doctor kept his medicines there and little Jack Thayer was in the same room several times

The trip to the dock was not an emergency sting, they just wanted to catch him before he boarded another ship to guarantee his participation. It's the same reason the hearing took place at the Waldorf-Astoria- ease, convenience, and the ability to get testimony from everyone they needed without chasing them all over two continents.

2. With that clarified, I'm not sure what you mean by "signal intelligence". If you are asking what information was caught via wireless- the answer is "all of it". The living, the dead, the details- all were transmitted and intercepted by radios all over the North Atlantic and the north eastern seaboard. By the time Carpathia arrived, the general story was well known and published in the news- after 4 days of rumor and speculation based on wireless interception (all saved!, 1500 dead!, Mrs. Astor maybe dead! Being towed to New York!)

I might be able to help you more, just wanted to make sure I understood your question and clarify what seemed to be a few misconceptions.