As usual no straight answers can be given to these questions. Will the shots be crosstalk free? No. The retrofocus Rodenstocks are designed to be crosstalk free with Dalsa 6um, and that's the limit. Every sensor after that get crosstalk issues to some extent.
Will it actually be visible? It depends. Will you actually care? Maybe, maybe not. Depends on how important you think color separation / tonality is and how you good you are at detecting degradations of it.
The 28HR works better than the 35XL. For center shots you'll probably be fine, and since the 28HR only have 70mm image circle you can't shift much anyway.
The 45 and 55 Sironar-Digital is analog designs and thus not as retrofocus as the Digarons. They've not been tested much with these sensors AFAIK, but the 55 is probably similarly demanding as the SK60XL, fine with center shots, problems with large shifts. The 45 is probably similarly demanding as the SK43XL, if so it will be fine for center shots, but a bit problematic with shifting, although I guess you can do 10mm without noticing issues in most situations.
My guess is that your first impression if you do some casual tests will be that "this works", but the risk is that you will after a longer period of time either get used to less-than-top-notch tonality or discover that you do get issues in an image here and there.
If you get to test the back and you want to make a quick and easy worst case testing, then make an LCC shot with a red filter (you could tape a red gel on your LCC card), and then a normal one, and apply the normal LCC shot to the red shot, test for the shift amounts you like to use, in both landscape and portrait orientations. If it forms a perfectly flat red surface then you will have no issues, if you have a residual cast then you have some crosstalk that can't be canceled out and may pop out now and then in real images.
In some cases you can rely on manual color correction techniques as described here:
The Image Quality Professor's Blog » Blog Archive How to fix the sky with the Skin Tone tool
if you think that's okay it could be the sensor for you.
As you probably now I'm a bit biased in this as I certainly wouldn't make these type of sacrifices to get live view. One aspect that I don't want to jeopardize tonality and the other that I think "enough is enough", it's been moving in this direction for years and I don't think it's fair by the manufacturers to put incompatible systems in the hands of the customers and hope they won't notice. The Sony sensor is designed for strong retrofocus lenses and should be used with such.