Apply H4 EAD based on pending H1B/H4 extension?
Yes, you can apply for H4-EAD based on pending H1B/H4 extension pending.
What Receipt number to write in Q29 on form I-765?
Write the latest (pending not approved yet) I797 receipt number in Q22 on form I-765 for H4-EAD.
What i94 number should be written on form I-765?
Write the most recent H4 i94.
Will H4 EAD be issued with H4 extension pending?
No, it won’t be issued.
Even if you apply for H4 EAD based on H1B pending receipt number, USCIS cannot really work on it until your primary H1B/H4 extensions are approved.
The H4-EAD application would be picked up and worked on, only after a decision on H1B/H4 extension has been taken.
Note: If you apply with H4 extension pending, your processing time clock ONLY starts after your H4 extension has been approved. Until then, it is just hanging in there with no real action.
Complete process to apply for H4-EAD along with pre-filled I 765 form is available here: