H4 to H1B Consular Processing

My wife is currently on H4 with an EAD. Her employer filed H1-B Consular Processing and it got picked up in lottery this year. Her H4 stamp gets expired May-2019. Her H1B will get activated when she goes for H1B stamping next year. However, we’d like to stay in H4 EAD as long as we can. Can she go to India and go for H4 stamping instead of H1b? That way she can still stay on H4 and switch to H1B at a later point of time. Will it impact her H1B by any chance?