There’s mesh panels then there’s that slotted one.
If that’s something like ar500 steel it’d be a barrier that blocked a fair bit of spall just by being there.
It’s not a “spall liner” in the autistic must be named that way sense. But it is possible that was a design consideration for that piece.
It would block small shrapnel from entering the main area and it would block it from the main area to the driver.
If you feel like the armor protection of the Abrams is inadequate, move this conversation to the Abrams technical data thread to get that thread the attention it deserves. There you will find multiple bug reports that have been accepted by Gaijin that would significantly increase the survivability of the Abrams, but Gaijin has continued to procrastinate the addition of these bug reports for years. (M1 Abrams (all variants) - Technical Data and Discussion) The Eurofighter technical data threads, T-72, Challenger, etc, all have thousands of replies and likes while the Abrams has 50.
On the topic of kevlar spall liners, this is a highly debated topic with no direct primary sources stating its existence similar to the DU hull debate. Unfortunately Gaijin’s stance on topics like this are that they will stick to what is 100% certain. There will be no kevlar spall liners. So please, harass Gaijin on the outstanding bug reports in the link to the other thread. This includes a significantly strengthened turret ring, increased lower front plate and upper front plate thicknesses around the fuel tanks, increased gun mantlet protection, increased turret cheek protection, moving the hydraulic pump. I believe all of these changes would produce a greater sum of survivability than kevlar spall liners anyway. Make some noise.
softer materials produce significantly less spalling, and even very thin aluminum will either stop, or significantly slow down a lot of the spall created by the armor