When I said, I do not like immunities as they are, I suggested to change it based on number of players in the game - see this thread.
95% or 99% resistance is far better than immunities, but Conviction, Lower Resist and Cold Master to apply at full effect after the reistance has already been lowerded, that is not a good decision.
I’m no fan of immunities, I am no fan of no meaningful resistances to elements whatsoever like it is in D3.
A monster that is tough by having 95% to 99% resistance to a specific element is fine, but the New Sundered Charms are bad.