OK, so this is a far trickier question to answer than it may seem from the question. We consult with two different material engineers and both of them, independently from another, warned us against this manufacturing technique. Where you use an off the self plug (gamma-lid) that is then threaded into a non-gamma unit. If the Coyote or Mojave is using gamma's snap in ring, like you would use to convert a 5-gal bucket to a gamma lid, they are good to go. However if they are roto-molding the threads into their box which is likely low-link poly, then using a high-link poly or some other harder material for the plugs, their boxes will eventually fail to the stronger material of the gamma lid. As long as the threads are the same material as the plug all is well, or so I'm instructed by people far smarter than I.
On the Mini we decided to use a proven off the shelf marine hatch for ease of customer replacement. The threaded ring is through-bolted, with a 1/4" silicon bead to ensure water/air tightness per the manufactures instillation specks.
Having said all this, I've never handled either the Coyote or the Mojave, I'll head down to Cascade Outfitters and check out the Mojave box, I know they have them down there. Sorry this was such a long response.