With the user-defined "polyhedron", you can do, e.g., this:
R = BoundaryDiscretizeGraphics@Graphics3D[
Polygon[{{{0.9000000000,
9.803074361, -0.2788974201}, {0.6750000000,
10.19278579, -0.2270388454}, {0.4500000000,
9.803074361, -0.2935999100}}, {{0.6750000000,
10.19278579, -0.2270388454}, {0.2250000000,
10.19278579, -0.2379129589}, {0.4500000000,
9.803074361, -0.2935999100}}, {{0.2250000000,
10.19278579, -0.2379129589}, {0,
9.803074361, -0.3066046725}, {0.4500000000,
9.803074361, -0.2935999100}}, {{0,
9.803074361, -0.3066046725}, {0.2250000000,
9.413362929, -0.3638887807}, {0.4500000000,
9.803074361, -0.2935999100}}, {{0.2250000000,
9.413362929, -0.3638887807}, {0.6750000000,
9.413362929, -0.3472567826}, {0.4500000000,
9.803074361, -0.2935999100}}, {{0.6750000000,
9.413362929, -0.3472567826}, {0.9000000000,
9.803074361, -0.2788974201}, {0.4500000000,
9.803074361, -0.2935999100}}, {{0.9000000000,
9.803074361, -1.278897420}, {0.6750000000,
10.19278579, -1.227038845}, {0.4500000000,
9.803074361, -1.293599910}}, {{0.6750000000,
10.19278579, -1.227038845}, {0.2250000000,
10.19278579, -1.237912959}, {0.4500000000,
9.803074361, -1.293599910}}, {{0.2250000000,
10.19278579, -1.237912959}, {0,
9.803074361, -1.306604673}, {0.4500000000,
9.803074361, -1.293599910}}, {{0,
9.803074361, -1.306604673}, {0.2250000000,
9.413362929, -1.363888781}, {0.4500000000,
9.803074361, -1.293599910}}, {{0.2250000000,
9.413362929, -1.363888781}, {0.6750000000,
9.413362929, -1.347256783}, {0.4500000000,
9.803074361, -1.293599910}}, {{0.6750000000,
9.413362929, -1.347256783}, {0.9000000000,
9.803074361, -1.278897420}, {0.4500000000,
9.803074361, -1.293599910}}, {{0.9000000000,
9.803074361, -0.2788974201}, {0.9000000000,
9.803074361, -1.278897420}, {0.7875000000,
9.997930077, -0.7529681327}}, {{0.9000000000,
9.803074361, -1.278897420}, {0.6750000000,
10.19278579, -1.227038845}, {0.7875000000,
9.997930077, -0.7529681327}}, {{0.6750000000,
10.19278579, -1.227038845}, {0.6750000000,
10.19278579, -0.2270388454}, {0.7875000000,
9.997930077, -0.7529681327}}, {{0.6750000000,
10.19278579, -0.2270388454}, {0.9000000000,
9.803074361, -0.2788974201}, {0.7875000000,
9.997930077, -0.7529681327}}, {{0.6750000000,
10.19278579, -0.2270388454}, {0.6750000000,
10.19278579, -1.227038845}, {0.4500000000,
10.19278579, -0.7324759022}}, {{0.6750000000,
10.19278579, -1.227038845}, {0.2250000000,
10.19278579, -1.237912959}, {0.4500000000,
10.19278579, -0.7324759022}}, {{0.2250000000,
10.19278579, -1.237912959}, {0.2250000000,
10.19278579, -0.2379129589}, {0.4500000000,
10.19278579, -0.7324759022}}, {{0.2250000000,
10.19278579, -0.2379129589}, {0.6750000000,
10.19278579, -0.2270388454}, {0.4500000000,
10.19278579, -0.7324759022}}, {{0.2250000000,
10.19278579, -0.2379129589}, {0.2250000000,
10.19278579, -1.237912959}, {0.1125000000,
9.997930077, -0.7722588157}}, {{0.2250000000,
10.19278579, -1.237912959}, {0,
9.803074361, -1.306604673}, {0.1125000000,
9.997930077, -0.7722588157}}, {{0,
9.803074361, -1.306604673}, {0,
9.803074361, -0.3066046725}, {0.1125000000,
9.997930077, -0.7722588157}}, {{0,
9.803074361, -0.3066046725}, {0.2250000000,
10.19278579, -0.2379129589}, {0.1125000000,
9.997930077, -0.7722588157}}, {{0,
9.803074361, -0.3066046725}, {0,
9.803074361, -1.306604673}, {0.1125000000,
9.608218645, -0.8352467266}}, {{0,
9.803074361, -1.306604673}, {0.2250000000,
9.413362929, -1.363888781}, {0.1125000000,
9.608218645, -0.8352467266}}, {{0.2250000000,
9.413362929, -1.363888781}, {0.2250000000,
9.413362929, -0.3638887807}, {0.1125000000,
9.608218645, -0.8352467266}}, {{0.2250000000,
9.413362929, -0.3638887807}, {0,
9.803074361, -0.3066046725}, {0.1125000000,
9.608218645, -0.8352467266}}, {{0.2250000000,
9.413362929, -0.3638887807}, {0.2250000000,
9.413362929, -1.363888781}, {0.4500000000,
9.413362929, -0.8555727816}}, {{0.2250000000,
9.413362929, -1.363888781}, {0.6750000000,
9.413362929, -1.347256783}, {0.4500000000,
9.413362929, -0.8555727816}}, {{0.6750000000,
9.413362929, -1.347256783}, {0.6750000000,
9.413362929, -0.3472567826}, {0.4500000000,
9.413362929, -0.8555727816}}, {{0.6750000000,
9.413362929, -0.3472567826}, {0.2250000000,
9.413362929, -0.3638887807}, {0.4500000000,
9.413362929, -0.8555727816}}, {{0.6750000000,
9.413362929, -0.3472567826}, {0.6750000000,
9.413362929, -1.347256783}, {0.7875000000,
9.608218645, -0.8130771013}}, {{0.6750000000,
9.413362929, -1.347256783}, {0.9000000000,
9.803074361, -1.278897420}, {0.7875000000,
9.608218645, -0.8130771013}}, {{0.9000000000,
9.803074361, -1.278897420}, {0.9000000000,
9.803074361, -0.2788974201}, {0.7875000000,
9.608218645, -0.8130771013}}, {{0.9000000000,
9.803074361, -0.2788974201}, {0.6750000000,
9.413362929, -0.3472567826}, {0.7875000000,
9.608218645, -0.8130771013}}}]
];
RandomPoint[R]
PS.: I have no clue at all what this new datatype is supposed to ship what is not already provided MeshRegion
s.
N.B: The above answer will work on very limited cases and will fail for a polyhedron if the vertices of any one of its face are not coplanar