I'm not familiar with Preload, but it's possible that another option would produce the results you want. Depending on the DE you choose, there could be an easy way to have applications start automatically when the OS is started.
And all editions of Solus support hibernation. That's the mechanism I use with all my hardware, and also all my virtual machines. Since I don't know you yet, I'll assume you're not familiar with that process, and briefly explain it here.
Hibernation simply involves copying the contents of RAM to a SWAP partition, then shutting down the device. Upon startup, those RAM contents are restored to ram. The result is a continuation of the presious session, from exactly where it ended.
Does either of these options sound like a good alternative to Preload for you? If you're NOT already familiar with hibernation, just say so, and I'll provide more details. Meanwhile someone else here may be able to answer your original question about Preload. I just wanted to point out that there may be other ways to accomplish what you need, that I know are available here.
