Confused on advice I'm getting for attic insulation

Good morning. I'm a homeowner and have a few questions. Recently during the last snowstorm we had large icicles and a few inches of ice form in the gutters. Has happened before but never paid much attention to it. Did some checking and the advice was to better insulate the attic crawl space. About 2/3 of the space has plywood floors with old batt insulation under it, a lot of the rest has the original brown paper from 50 years ago. Had a contractor in who suggested blown in cellulose. He will pull up the plywood, remove all of the old insulation in the entire attic and put back down the boards and blow in insulation under them and then dam up the non floor areas and spray in about 15 inches. So far, so good. We are also considering installing a split system throughout the house and that contractor is suggesting not to use cellulose in the floor but to use spray foam in the rafters. While that seems logical to prevent air loss through the roof to stop the snow melt/refreeze cycle does it do anything to help better insulate the living spaces below? I read someplace that if I do put foam into the roof beams that I should remove all of the insulation on the floors. Getting pretty confused by all of this and your guidance appreciated.

Best... Steve

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