When I owned my swiss rifles until I just sold them on the EE I went through a lot of aftermarket stuff, and ended up returning to the manufacturers product in the case of stocks.
FYI AR stock adapters do not allow the use of AR height optics without the use of a cheek pad / cheek riser of some kind as they put the stock at the same height as factory (except for the rare and OOP DDLES). A cheek pad will then remove the ability to shoot it folded. AR stocks also will require you to cut a hole in them to properly engage the folding lug. At + / - $300 for the adapter only to introduce a new set of stock issues, and not solve any of the original issues, it is a exercise in futility IMO.
Those ACR adapters look cool and have potential, I just don't know how strong the 3d printed material would be compared to the factory stock. Also unless it's hard attached to the lower that picture posted above is a little misleading, the LOP would be longer as the adapter attaches to the folding mechanism, then the ACR stock attaches to the adapter. It will have two folding hinges on the right side, and only one will be operational. It will add more weight to a already heavy rifle that is nearly impossible to shed in other areas.
Ask yourself what you require in the stock? If it's simply adjustable LOP then the factory collapsible achieves that.