Sure - each man is open to express his opinion here ;-)

Mine is that we should suggest ideas that are tried and tested by the writer

So please leave the marriage suggestion for married guys to share from actual experience

I could suggest outrageous ideas to you, would you like me to? No
So I'm asking you here the same way. Ok I think I made my point

And you base it on the premise as you wrote "That these men may be addicted to porn, or heavy porn users, is not enough reason for them to avoid the shidduch process".

Actually it is a pretty good reason to delay the process, and it all boils down to what their coach / rabbi directs them to do.

In a nutshell; you are the one that created a problem for these unmarried guys and then offered an unsubstantiated solution

Please rethink over the whole thing

Who says you need to say anything? work on yourself and stay strong and move on. why do you need to portray yourself as a negative person ??? im also shidduch age and i personally think that there is no reason for any of us to say anything, as long as we are staying strong.
Correct me people if i am wrong !!!

I do not know why you think you have to share this. Everyone does things wrong, and we all have bad habits. If you are working on yourself, and seeing progress, you might not have to say anything at all.

Should you decide to tell, I don't think this is something for a first date. I was seeing a psychologist while I was dating. The person I was seeing is also a Rav whom I highly respect. (I knew him as a Rav first, and as a psychologist later.) For my particular issue [nothing having to do with anything on this forum], his advice as a Rav, was I don't think you have to tell, if you want to you can, and you have to decide if you want to or not. 

I am neither a Rav nor a psychologist, but my advice would be similar:
If you are able to carry on a normal life, and your addictions don't interfere with normal daily activities (i.e. you can maintain a steady job, can share the responsibilities of running a home, are reliable) you do not have to say that you are having issues with masturbation. This is especially true if you are fighting the addictions. Once your relationship gets deeper, you can if you want to, reveal that you had/have issues with porn. Should you tell, then tell her what you are doing to fight it, and any thing that will affect her or the household. (i.e. no computer/TV or heavily filtered internet, your inability to go to certain places because it is too much of a nisayon).

My personal experience tells me that a woman will respect someone who is honest, and who is looking to grow. If you say, "I can't go to this and this place because it's too great a nisayon", she will respect you, and your struggle to grow. 

If your relationship with your fiancé/wife is strong, it may be enough just to say that you had issues, and that you worked on yourself, and it's no longer a burning issue. If that is the case, you may not ever have to reveal all the dirty secrets, or as time goes by, you may feel strong enough to tell all.

If your addiction is consuming you, and you can't function properly in society, then you should not be in shiduchim  until you can.

I hope this helps. To put things in perspective, I've been married for 13 years so far.