I think this has all been said, but maybe just to be clear on one thing:
The original questions was basically about how to get the playback experience with or without gaps as it is on the CD. Basically you want to playback an album that is one continuous stream of uninterrupted audio exactly like this, but if there are some small pauses in between tracs those should be there, too.
Now there is one wrong assumption: That tracks get ripped without the pregap included by default.
If the default would be indeed to exclude the pregap everyone would have had this problem the last 25 odd years of ripping CDs. You would think one would have come up with a solution.
And actually this is for most practical applications a solved issue: Include the pregap in the previous track. For most practical uses this totally solves the issue. Audio can be played back as is without gaps. No need for specific file formats with advanced features like indexes or special metadata support in players. It is also what makes sense if you have a digital download with separate files. It would be strange to have small inter-track files or something like this.
So this solution works good enough for most cases to a degree that probably most listeners don’t experience this as a problem at all as long as their player can technically do gapless playback.
There are of course limitations for this. E.g. if you have crowd noise and applause in the pregap this is fine if you playback the entire live album, but if the track is in a random playlist it can be annoying.
So I understand the original post more as a discussion to see if there could be a more sophisticated solution that takes care of such things and e.g. allows to more exactly specify such inter-track audio. But while I find this interesting as a theoretical discussion, but I also think that the current solution works well enough that there is not enough interest to change the implementation of current playback software and devices.
Not against having the ability to store such information in MB, though. More details about the actual structure of a CD, why not. If someone cares to extract and submit this it sounds fine to me. I just don’t believe it would help in any way for better(?) gapless playback in players.
Yes, absolutely. But this is a technical deficiency, no amount of metadata can change that. It’s not because the players insert some gap, but because they don’t take care to produce a continuous audio stream also on file change.