I haven't yet, but I'm thinking of getting some metal mesh like this: https://www.amazon.com/dp/B08PBM1C2F/ref=cm_sw_r_awdo_0SAH7F8ERPQFS0MT11G3
And adding some maybe half inch L beams as the lip/rim with some flat beams across the middle for support, all glued together with JB WELD lol.
As for distracting them, it's really up to THEM. I've found that sphynxes are more than happy to make up games if you pay attention and try to figure out the 'rules'. And you can entertain them all day, but I really don't trust them unattended to leave something alone. Safest bet is to keep the lizard in a room with a door you can shut if you're not in there to supervise. Or reinforce the tank lol.
AggAuto Universal 40"x13" Car Grill Mesh - Aluminum Alloy Automotive Grille Insert Bumper Rhombic Hole 6x12mm, One of the Most Multifunctional Shape Grids Black https://www.amazon.com/dp/B08PBM1C2F/ref=cm_sw_r_cp_api_glt_fabc_Q5J9W79KBRRER442YXG8
There's plenty of options from the automotive world:
But depending on how your skills are, it's going to be tricky getting a nice finish around the edges with how the original grille fits snugly into the perimeter slot.
At some point I want to revise my 2 x 140mm fan 3D printed top to have an all longitudinal grille like the Iquinix ZX-1
https://iqunix.store/products/itx-case-zx-1
I just need to find a few hours!