What I am trying to achieve is:

1) See if there is any bolt-on alternative if you have a cracked turbine housing. It's confirmed that there isn't now. Anything you want to put there which is not original, will need adapting.
2) Given that adaptation of a different unit (Housing or full turbo) is the only option, what is the least labor/adaptation/surgery intensive option.

I am aware of the many equivalent o improved T2 CHRAs available around, but again I'm talking here about the frequent cracked turbine housing problem. My own turbine housing is so far OK, with the usual minor hairline cracks, but should it die completely or would I wish to bolt in something that provides more power reliably and with available spares, I want to know what options are out there that require less hassle. That is my goal right now.