As with any tool in development, web3tracer has a wishlist, also known as a known limitations list, where things that aren't just right (yet) get listed. Feel free to add your own as a comment!

• There is no GET trigger
  It would be nice to have a trigger like XDebug for profiling php scripts, so one doesn't always need to modify a file to profile it; the current approach offers more flexibility in that you can profile only selected pieces of code, but we will also add a trigger for convenience
• Not tested yet in a TS environment
  We are sure hoping for community support on this matter
• Not available on PECL yet
  We sure hope to get it listed there as soon as we have time
• No source code info
  In order to use KCachegrind's code explorer features, the module should output source code data, like files and line numbers for the sources and destinations of all calls. Although a nice feature, we feel we can safely sacrifice it for simplicity and performance for now.