the joke here is that SK as a whole needs an optimization update instead of a promo update, but i'll work with it.

the post that flowchart linked to is still relatively accurate. if you have 8 GB of RAM you could allocate up to 5 GB and still be okay as long as you're not an idiot running other resource-heavy processes like chrome in the background, since then it'll start throttling everything to compensate. you can use java 8 instead of java 7 and still be able to follow the instructions in the thread. on top of that, there's multiple GC processes that you can use in place of ParallelGC but unless you're familiar with what your system can feasibly do, you're better off with sticking to what was provided in the thread.

otherwise, the only other thing you can do to load faster is either make sure you have SK installed onto an SSD of some kind and continue to tweak your extra.txt settings until you either a) find a sweet spot or b) have to reinstall SK because you messed up somewhere.