Maybe I'm a purist, but I've always really enjoyed seeing a series of scrums where a dominant scrummaging team is camped out on the opponents' 5-metre line putting them under the cosh for 5 mins with scrum after scrum forcing the defending team to infringe and give up a series of penalties and the inevitable yellow card or sometimes even two.

Or the drama of the above (expected) situation being foiled by the defending team pulling a miraculous scrum out of nowhere that unexpectedly wins them the penalty and the chance to clear their lines.

Often these moments are momentum givers or takers - game-changing moments in many cases - and are, ultimately, what sets the game apart from Rugby League (for me, anyway). I really don't want to see the Rugby Union institution that is The Scrum diluted - but I do agree that somewhere in amongst the Rassie/Joe/Carling suggestions is the key to making it more appealing to a wider audience. Also, mic'ing the ref NFL-style feels like such an easy win - so fans in the stadium know what's going on.

I think you still get the dominant scrums with the "2 scrum" rule.
What would probably tend to happen in this case though is that the dominant team would end up pushing the other team over the try line and getting a try rather than the weaker team giving away a penalty try and a yellow card. 

But, as you say, you can lose the "drama".

A few years ago, we beat Exeter with a penalty try after 80 minutes had gone. I was sitting in the South Stand and it all unfolded in front of me and it was great drama.
But, recently, there was a game (Montpelier???) where there was an extended period in front of the North Stand. To be truthful, it wasn't the most exciting thing that I have ever watched. TBH, we had no clue what was actually going on as we could berely see it.

I'm very much against complicated technological solutions when the laws should be simple enough that it can be refereed accurately at all levels of the game.

But you know that ain't gonna happen. The laws aren't simple enough for them to be refereed accurately at the pinnacle of the game, much less understood by casual observers.

I don't buy into the attitudes which held football back for so long that you shouldn't bring in improvements unless they can be implemented at grassroots level. At this level people's livelihoods and careers can depend on a poor decision.