I am talking about keeping the data on my harddrive. Instead of two copies before the fork, use only one.
you mean
one copy of the chain upto block 478558
then a btc chain of 478559->ongoing
and a bch chain of 478559-556767
then a bch chain of 556768->ongoing
then a bchsv chain of 556768->ongoing
like this:
2009----------------------------------o-----2018 btc
|
2009
----------------------------------o---e-2018 bch
|
2009
--------------------------------------e-2018 bchsv
instead of this:
2009----------------------------------------2018 btc
2009----------------------------------------2018 bch
2009----------------------------------------2018 bchsv