i agree to some extent with what has been said above
50g ED will be sufficient to stay in ketosis for most
as for the refeed? 250g? not even going to hit the sides. look at supercompensation and jig your training to suit or change the structure of your CHO intake to either isocaloric (as stated above) or employ a TKD
IMO a CKD is ace, you will not lose muscle mass, you just have to get into ketosis, stay there until the 24-48 refeed and then utilise the maximal glycogen stores to fuel your workout
ketosis is fine in terms of energy levels once the brain utilises ketones over glucose...until that point you will feel like shit
but once you get there, for most, its fine
low carb on the other hand IMO/IME has all the bad points of ketosis with none of the good ones
either up CHO or run a CKD would be my suggestion