In French Defense 2 (1998), IM Nikolay Minev mentions the DDG in the comments of one Alapin French 3.Be3 game. He suggests the following new ideas for two DDG variations:
1.e4 e6 2.d4 d5 3.c4 dxe4 4.Nc3
A) 4...Bb4 5.Qa4+ Nc6 6.Be3 Bd7 7.Qc2 f5 [ECO]. Minev suggests 8.O-O-O!? Nf6 9.f3
Editor continues: 9...O-O 10.Nge2!? (10.fxe4 Bxc3).
B) 4...Nf6. Instead of 5.Bg5, Minev suggests 5.Be3 Be7 6.f3. Editor: This naturally looks OK, because Be7 is a passive move.
Minev writes that his suggestions deserve attention but also more analysis before put into practice. Does that mean that the DDG in general is then "ready for practice"? He gives 3.c4 as dubious, of course, but does not give any textual explanation.
It is noteworthy that Minev does not even consider 5.f3. Lately I have learned that delaying f3 is probably a good idea: White will have problems if Black does not accept the sacrifice. The main ideas are as follows:
A) 4...Bb4 5.Qb3 Nc6 6.Be3.
B) 4...Nf6 5.Be3 Bb4 6.Ne2 (6.Qb3!?), threatening 7.a3!, after which the e2-knight can attack the e4-pawn either from c3 or g3.