I don't think it's wise to add much to lye solution ahead of time, other than tussah silk. When I've tried that before, stuff precipitates out, as you experienced.
When I make my CA + sorbitol solution ahead of time, I refrigerate it if I won't be using it within a few hours. Otherwise, it becomes fertile ground for growing stuff, long before you can see it or smell it to know that it's gone bad. You can certainly do the same with your CA + salt + sugar solution. The worst that might happen is that you have to reheat it just a tad to get stuff to redissolve. It's so much easier and safer to do that without any NaOH in the mix.
By making a separate additive solution, in addition to the lye solution, you can easily blend the additive mix into your oils, before adding the lye solution. If I'm adding goat milk powder, I first stick blend it into the CA + sorbitol solution, and then blend it again into the oils. If it is a single color soap, I also include the EO or FO in that mix. That way, I don't forget to add it in later.
My soapy thing today: It really started yesterday, with rendering/cleaning several pounds of lard and tallow. After adding some ROE, the cleaned fats and other oils were mixed up to replenish my master-batched oil bucket. It should have been pretty quick process, but SoapmakingFriend was being quite difficult. Because I was trying to use up some leftover bits and bobs, there was a total of eleven oils in the mix of 17,000+ grams.
After entering all of them and hitting Save, the calculator erased everything and said, "Enter amounts to see the results." It did this TWICE.
The third time, I clicked SAVE AS instead of Save - and thankfully, that worked.