Any 2k solvent based epoxy, sealer, primer what ever they want to call it is pretty much the only air tight spray on product for direct to metal applications that isn't a baked on product. Its a bitch to sand , flexibLe and tough as nails compared to other products, most production shops hate it because time is money to them. The textured stuff is just a gimmick when not used for grip or anti chip applications in areas that see high wear like a truck bed, on a undercarriage out side of off road stuff, its mostly used to hide shotty work, that's all I'm saying, so its a giant red flag to me. I'm sure yours will be sealed with epoxy before any paint work is done.
It's like when you look at a used truck these days and the all got a fresh coat of blacked out under coating sprayed right over the rust. Looks nice at first glance, won't look good done the road lol. Same reason rock guard is a textured product, it has some flexibility in it to avoid chips down to primer but its pretty pointless on the undercarriage of a street car, you can tint sealer or just do a dust coating like the factory would with the color, there not high impact areas, most rust and rot is from bad drainage and crap build up holding moisture or brine, why adding a textured surface to those areas is a bad idea it just helps collect more build up in neglected areas