Not sure a crumb tray removal will fix his issue.
Even when propped up from the bottom the sides of his tray are going to extend past the half inch limit and bang into the head.
You can try a disassemble, but that will be impracticable for a lot of pre-made items you want to laser on.
One thing to try is prop the tray to where the high side edges are at 2 inches max (to miss the head).
Then play with defocus score to give the design you want on the tray surface.
One benefit to doing a design like this is it will be a faster burn using a score instead of a raster. Also, making a design with just vectors is faster than trying to get a raster ‘just so’. Not all designs will favor a wide defocus burn, but many will.
Plus it is fun to play with things and see what it comes out like.
As always, I would place some scrap or cheap materials in place of the item of value, just make sure the actual depth is the same for practice as the final material will be, since a defocus will make large changes to the art at different actual distances. (So if the tray bottom is actually 1 inch below the laser head when positioned to not hit, so should the practice board). Also be aware that since the laser is not focused properly, it may require more than one pass to get it dark enough to satisfy.
Here is an experiment I did with defocus.