1.4 will be all about architectural updates to StarTools, which includes exactly some of the stuff you mention! A while back I mentioned
project saving which should do waht you're asking for (and more). It's early days for 1.4 - I'm just happy I got MacOSX 64-bit support finally mostly dealt with - but you should see more improvements like these as we go along.
As for increased usage of multi-threading, multi-threading is not always a silver bullet
and is highly dependent on the algorithm. Single-threaded algorithms that are memory intensive can faster under some circumstances than their multi-threaded counterparts. It all depends on how long threads have to wait for access to the memory bus and/or cache versus the gains made in processing speed. It's a delicate balance with sometimes less than intuitive results. ST in particular is much more memory-heavy (e.g. Tracking) than other programs which compounds this. It's also the reason why using the GPU (for example by employing OpenCL) is less appropriate for StarTools than it might be for other, less complex filters/programs such as those in PhotoShop or PixInsight.