I shot the collars for awhile years ago....and IMO they are a wasted effort for a minor benefit in a very small % of scenarios if at all. Then there is the big negative in some targets like carpet bales and the Morrell type targets with pulling your arrows.
I think Collars are a solution looking for a problem. Many threads on the HIT inserts- the experienced guys like them and have not had problems. The half outs CAN be a problem when it comes time to get your BH's perfectly concentric.
IME, you are focusing on the wrong factors. Pick a over spined arrow shaft [more durable], mill the ends on a jig squaring them pre assembly- [the saw leaves a ragged edge] That squared end makes the whole assembly stronger with your BH's seated better on the shaft and insert mitigating the need for anything else like collars and half outs.
Assembly has proven to be more important than all of these expensive components.