The SoC may be the same platform, but the hearing aids are not at all the same in software. Judging from the spec sheet it appears the Wave is the counterpart to the lowest level (of four) Paradise, the 30 Essential. The KS 10 is equivalent to the Paradise 90 Premium, the highest level. You should expect the KS 10 to be substantially better.
However, walking around the store tells you very little because that environment is very different than your day-to-day environments. (Unless of course, you work in a Costco or similar big box store.) That’s the purpose of the trial, to see how you fare across environments.
You have mild-to-moderate-to-severe loss, so you definitely want a proper fitting by a skilled HIS or Audi. Costco will have programmed the KS 10’s to “first fit”, which is typically 80% of prescription. So expect a series of adjustments to get to your target and fine-tune to your preferences, which the KS 10’s give you much more of than the Wave’s.
As far as DIY programming, @Edma gave you good advice. I’m only just starting on that path myself (also a retired engineer) and I’ve found that, while the software is certainly not daunting, it does require having a good understanding of the theory of operation in the instruments and particularly the inter-relationships of the settings. You can actually find all that info free online. Suffice it to say that much more is involved than just setting the gains to reach the frequency targets.
Good luck!