gestalt11 do you have more observations about shops and items that are too rare/common? That can be good feedback. You probably know the traders very well with all that savescumming.
Also, have you considered just rolling with what you get, no savescumming? Try it as soon as you're comfortable with the difficulty, you might like it. For me, Underrail is more fun when there's a possibility to find gear upgrades or useful components almost anywhere and my character's power is reasonably limited by not having the absolute best gear. Finally crafting your perfect energy shield (or any other complex piece of gear) is very satisfying when it has taken time, effort and luck to gather the parts - rather than few minutes of savescumming. There are few opportunities to reliably get high quality components. Since you mentioned power cores - there's a quest that rewards you with a 100+ quality plasma core. It feels like a great reward if you don't spend hours savescumming electronics shops.
I save scummed specifically to characterize the type of item you can make and the nature of generation at the stores. Not to "win" the game as I have purposely stopped any playthough at a partial completion of objectives for the core city section, i.e. one playthough did beast but not hunting camp etc. I am sure you can playthrough the game just fine without scumming for quality stuff or even crafting things at all.
The issues with what you are saying about crafting the "perfect" taking time is that it will never happen. Its a fine idea in theory but in practice the likelyhood of ever getting the components without save scumming are vanishingly small so 99% of playthrough will be onto the next tier before it ever happened. The 3 hour figure I said above is actually fairly low, but good enough to use. That is about 250 store generation events. Just to get one run at what you need. That is small enough that you should assume you will never actually create a top notch shield in the Core City tier of the game. Can it happen? Sure you can always get lucky but for most people it will never happen and for the people it does happen for.
Does it actually matter whether someone crafted a shield with all 75 quality items intstead of all 89s? Sure it matters some but its not going to make the game hugely harder. Its not a balance issue, really. It just setup in a way that will very much encourage save scumming, which generally means its not working that well.
Also if you are doing a build like, say pistols with energy shields, then you need 3 or 4 good power cores. The power core is most important for the shield. But even so there is no chance in hell you will get 3-4 quality 87-89 cores before you finish the mid tier and get to the next tier of crafting.
I think currently the worst thing about the stores is that some components really need to show up in a pretty regular manner. One of the reasons to have a robust crafting system is to reduce the dependence on RNG not increase it. I just don't think being able to make a good energy shield via crafting should be heavily RNG dependent. The whole point of stores is to make this not the case really. You spend an asston of extra money so that you can get pretty close to what you want. Stores do not currently work that way. They are currently rather bad slot machines.
Consider for a second that things with no quality at all, like the barrels on guns whose sole purpose is to be a selector into different gun sub-types are randomly generated. You go to a store wanting to make a .45 pistol fine there is variance in the quality of the Hammerer frame, but why do I have to wait around for a whole frigging hour because the store only genreated 9mm and no .45 pistol barrels which have no quality rating anyway? Really its assinine. There is nothing fun or interesting about that, its just fucking with people. Fuck yeah I will save scum that if its that way on release. If I invest 80 points into two different crafting skills and accumulated the other three parts I want but due to bad luck no shop has a .45 barrel? Fuck that.
In other words if the game's shop work the way they currently do there is almost no chance I will not do at least a modest amount of save scumming on a crafting character just because I see absolutely no point in waiting around to get the thing that determines whether I am making a .45 or 9mm and has not effect on how good the gun is. Perhaps I might consider not save scumming if it were only quality at issue. Similarly the ability to get certain modules vs other is clearly not balanced and I would probably save scum that as well. It is extremely easy to get high/med/low shield modules and very hard to get, for example, a gun smart module. With the current system I would be ok not save scumming for shield modules and would almost certainly save scum for gun smart modules simply because having a shop actually spawn one is too rare and I do not want to wait forever to use some good frame I bought or found because I find one anywhere and may never actually find one, screw that noise.
Suppose I want to make a Tactical Vest that uses the plate that gives a bit more DT rather than the typical plate. The generation in stores on those is low enough, that most people will save scum it. But why? Those plates trade increased DT for less resistance. That should be what determines whether people make one vest or the other not the bad drop tables in the shops. Its fine to have a high quality resin plate be rare, but having the plates themselves be rare is kinda dumb when put into context.
