I am seriously tempted to buy a 3D printer and create a COB mounting/reflector solution that is easy and cheap.
Here are our options as I see it.
1) Ideal chip loc holder + reflector adapter + LEDIL angelina $10-14 per cob and you have to source 3 different parts.
2) BJB holder + LEDIL. good luck finding the BJBs at any US retailer.
3) Khatod : expensive , available direct, but high MOQs 50+ units min order.
4) Kingbrite holder/ideal holder plus lens: heavy, massive lens needed to fit 3590. lenses to keep clean. extra holes to tap
5) TE connectivity Lumawise Z50 holders: limited availability on mouser for larger COBs