I run Onyx that does the same thing and it doesn't help. I leave the processes run and don't abort so the jobs get a chance to complete.
My issue has been around for some time and I have dealt with second level support at Apple including providing all kinds of log files and no resolution came out of it.
Over and above what I was reporting in my own thread submission, I discovered a bug in iTunes with videos so at this point, I don't sync any iPhone/iPad using iTunes to these devices as when I do, as soon as I plug any iDevice, iTunes presents me with a spinning beach ball for 5-10 minutes. This issue occurs even after using the function with iTunes to create a new version that is iPhone or iPad friendly. I'm talking about short videos of 2 minutes, somehow, syncing some videos results in iTunes hanging for 5-10 minutes every time I plug in an iOS device even though I specifically have the switch to prevent auto-sync.
My diagnostics included replacing my MacPro (I had the same issue with an older version MacPro and I replaced to a new MacPro this past January, rebuilt it all from scratch so no migration of anything), also tried creating a brand new user on my MacPro, loading my entire library into iTunes (took 4 solid days/nights), getting a completely separate iPhone with nothing on it then syncing some music, apps,... Another test was buying a totally different Thunderbolt hard-drive, moving my music library to it then rebuilding iTunes from scratch,... None of which resulted in any resolution to my issue.
My computer runs fast, very fast, with everything else including video editing and large photo edits, and this using the same drives as my iTunes library.
Although it may be true that some of the comments here are to vent, do not assume that nobody has done any kind of serious troubleshooting. Although the tool that you mentioned may be useful, it does not resolve the issue with iTunes that I think a lot of people are experiencing. I for one have over 30 years of technology background, have done everything I possibly could to isolate my issue. Even Apple's second level support didn't find the issue after spending many many many hours connected to my computer to monitor it. Engineering was engaged although they've probably got bigger issues to address than my computer iTunes issue, none of us know where a large library iTunes issue is in their priority list.
The only common element with that I cannot eliminate is: iTunes. There is something not quite right with something although I don't think any of us can resolve this on on our. It resides with Apple's engineering. Every time there's a new iTunes, I keep hoping that it will resolve the issue I have, sadly, this has been going on for years and despite progressing to every operating system, the issue remains.