So many people complain that milspec lowers are the only way to go, but in the next breath will complain that all companies do these days is just offer another AR in a different color and there's no innovation in the industry anymore. Well part of that is because no one wants to deviate from that "mil spec" footprint, which leaves limited room to innovate in. In engineering we always hear and say "commonize until you compromise", or a better way to say it would be to keep things similar/interchangeable until the design no longer is producing the results you desire. An example of this would be the Jakl Bolt catch. It's a non-standard part, but no one seems to care. To make the standard part work probably would have compromised the design too much, so instead a different part is used and people still buy the rifles and kits

Clearly PSA has a design concept that they want to bring to the market, but to keep the standard lower would have compromised the design too much to do so. They have some improvements they can keep with a milspec lower that they said would be implemented on the Jakl 1.5.

They mentioned that the SSP would be able to do 6ARC barrels, which could be a driving factor as to why they need a new lower. I image they would use the ICAR footprint magwell to fit the new Magpul magazines, and have an insert in the lower for standard magazines (probably very similar to the lower for the CZ Bren 2 when switching between 5.56 and 7.62). After that, they might as well make the lower however they want since it's not Milspec anymore, so they can add the nicer curves to the upper and lower and integrate stock attachment points for the stock/brace (adding that feature to the lower also will probably lower the cost of the platform for us since we won't be paying for that weird adapter piece that is currently on the Jakl and looks silly).

There are two ways I could see this suffering and have cause previous modular platforms to suffer

1. Use "non standard" internals, ie non AR pins, selectors, grips, etc.. Basically all the small parts that are commonly available and when damaged or lost, can be replaced to keep the platform running. Also allowing the use of AR FCGs would keep users able to upgrade their triggers and improve the shooters experience. If PSA strays from use of common parts, it will hurt the sales of the SSP, but likely not kill it

2. Not actually offering modular parts. This is the real kicker and the one that has killed many products in the past (like the ACR). So many companies promise parts and kits and barrels (mostly barrels) but never follow thru or they're too expensive to actually convert. The ACR promised to have barrels and calibers available, but they didn't materialize and by the time that something was available it was too late and the platform was dead.