If you don't want to use a snubber, then you'd best not get more than 50' of chain. I think that the general view that I have is if you want more, then you'd better-off planning on using full chain for most of your anchoring. That would mean a 100-150' in the depths which you've suggested.

Do you plan a rope to chain splice? That has an impact of the real ease of retrieval as opposed to a shackle at the juncture of the chain and rode. The deeper the water, the heavier the chain's load on the person(s) hangling the retrieval.

Have you had any issues with your current rig? Have you "challenged" it? Do you find it has failed you in any circumstances? I'm not sure you'll gain that much unless you go to all chain.

We have 250' of chain in front of 50' rode. We very infrequenly have had had anything but all chain. Our 60# CQR has stayed where we put it (unless I really didn't set it right, or put in very soft mud or leafy bottoms).

On our previous boat (a Sabre 42) we had about 40' of chain in front of a rode. Our 35' CQR keep us where set it in up to 45 knot sustained winds in the Chesapeake.