How to keep decorations from killing new grass

Hey guys, I have 5 large tombstones that I put in the front yard every year. Prior to now, I wasn't very worried as the grass was mostly weeds. This year I did major landscaping and got new flower beds and sod. I don't want to kill the grass.

I usually leave my decor up all month in October (4 weeks). I'm thinking of creating 2-3 inch PVC pipe stoppers. Where I can cut some PVC pipe down to 2-3 inches, spray black and slide those over the rebar before putting my tombstones down so they don't squash the grass and let the grass grow long enough to camoflauge it.

I'm getting zoysia which is very shade tolerant. Would I still need to remove the tombstones to give the grass some sun time? I got to be honest, I'm not really interested in taking them down every day, but could maybe do it 2-3 times a week to give the grass a break.

It's also fall and the grass will start to be going dormant. In the past, I had no PVC stoppers, and yes, I would have brown spots when I took them up, but then the whole yard would go dormant and you couldn't tell. Then by next spring everything would green up fine.

How concerned should I be?