Here is the Shimano Service instruction for that model DR....
https://si.shimano.com/pdfs/si/SI-U-005-000-00-ENG.pdf
They do the big big + 2 links. And this is without the chain running through the DR's pulley wheels. However still this isn't a guarantee. You still need to be aware of all the places for concern regarding the chain length as specs on paper can't guarantee your specific setup isn't unique in some way.