Forget the scramjet on Skylon type vehicle

Scramjets are too heavy and the performance isn't good enough with a thrust to weight of only 2 to 1

Scramjets aren't likely to ever be used to transport people, in my opinion.  Not good enough.

Here's the relevant post.

It seems that the Skylon may dump a lot of hydrogen overboard, but that isn't confirmed.  It's possible that there may have been a use found for this hydrogen as opposed to just dumping it.  Depending upon memory, there.