Why not make a MR into the main game for some of these sprites?
AFAIK, they are too far outside the "style" of the base game for them to be considered.
Seems like a missing/misnamed png file, here's a quick edited save and visual example. Still happening as per 5.7.5. I shall now return to lurking, again, thank you for your work, good luck.
It's not that the graphics themselves are missing, it's because FireMod is generating incorrect paths to the graphics it's looking for (though that looks like the same thing to the player when it just tells you an image is missing). I posted the following in the DoL Modding Discord's FireMod channel some days back:
"The new official version by fire seems to suffer from the same issue that the old unofficial version did, wherein the xrays for strapons and male protagonists do not work
I believe the issue can be resolved by changing these two lines:
Ln 213069:
<<set $_filterColour to ($options.tanImgEnabled ? "penisRed" : ""

>>
->
<<set $_playerPenisSprite to ($options.tanImgEnabled ? "penisRed" : "penisWhite"

>>
Ln 213091:
<<set _xrayPlayerPenisPath to _img + $_penetratedSprite + '/xray' + $_penetratedSprite + $_filterColour + $_playerSize + _cumString + 'cock.png'>>
->
<<set _xrayPlayerPenisPath to _img + $_penetratedSprite + '/xray' + $_penetratedSprite + $_playerPenisSprite + $_playerSize + _cumString + 'cock.png'>>"
But there are other issues as well, such as strapons not having the correct coloring, that disturbed, the unofficial FireMod maintainer, already fixed or at least made better that the official FireMod has not adopted.