Consular Processing

Currently, I am On My H1B, filled H1 extension on time, before I -94 expiry, ( Perm, I-140 Approved ). When H1 extension pending in normal process can I apply for a change of status to F1 by using the H1 receipt number? While I am on F1 if my Priority date is current, can I Adjust my status / file (i-485) when I am on an F1 visa? Will it be an issue If I am F1 visa to Adjust my status if priority date is current?

My employer has filed my h1 and asked for a change of status with H1 filing and got an RFE(As i am filing from CPT-F1 to H1) relating to
--Maintenance of Status<br>
--CPT Related<br>
--Multiple years of CPT at the same Education level<br>

The lawyer is asking me to change from Change of status to Consular Processing and go to India and stamped and come back.

My H1B (6 years) was from 10/1/2004 - 9/30/2010 from 5 different companies.
Company A - PD(EB3) - Jun 19, 2007, I-140 applied on July 9, 2007, I-485 filed July 17, 2007 - got laid off Oct 31, 2008. - I-140 approved on Dec 29, 2008.
Moved to Canada in July 2012 and became Canadian Citizen in Apr 2017. I have been keeping Advance Parole active by visiting the USA every year.
Now I want to add my family in Canada(wife(Indian Citizen with USA visitors visa) and kid(Canadian Citizen)). Do you recommend AOS for myself and Consular Processing for my family?

I have an approved I-140 and a Pending I-485 (Since July 2007 Employment –Based Adjustment of Status Indian Passport Holder is submitted Application ). Since presently there is very large backlog I decided to move Canada 2009 since I am Stay in Canada and now become Canadian citizenship. <br>
1. How to switch to Adjustment of Status to Consular Processing?<br>

2. How long would it take to switch from Adjustment of Status to Consular Processing?
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3. How to inform to USCIS to change my citizenship Indian to Canadian.