My personal opinion on the new texture generator is that it is over-doing the relief and makes the planet look smaller. I prefer:
float normalScale = 1 << (_planetScale/2);
... which gives a flatter look.
Before anything, just wanted to mention that the algorithm does produce a bit intense relief, but not always Some planets seem to have smoother surfaces, or this might be simply an impression generated by higher percentages of water areas, but in any case the point is that some planets do appear rough and some less so.
Having said that, I think your method of relief control is somewhat too "binary", i.e. too much yes or no result. If I wanted to have a relief intensity somewhere in between your modification and what we have now, it would be very difficult to achieve. Instead, I experimented a bit with multiplying the standard normalScale with a factor and this is the result for factors between 10 and 90 percent of the current standard:
(4320 x 2700 res png here
In the Test Release builds of the game, you can now use the user defaults parameter "p3dnsf" and set the intensity factor for the generated relief yourself. It is meant as a test feature only and there is no sanity checking for its value. You can make it even more intense than what we have now. Here is what it looks like for a factor of x2:
and, in case you would like to go completely gung-ho with it, here it is with a x5 factor:
Edit to add: Note, this is Celearen in G5, one of the most relief-intense systems I could find as an example. Other systems are normally a bit flatter than this.