I have gone through the AIPP and would like to share some information based on my personal experience for those who thinking to apply or are in the process. I applied as High skilled worker
Guys before you apply consider doing some reading on employment law in the province you applying for. My case is long and complex but to cut it short I was unfairly dismissed and replaced with local employee. The employer was adamant that because I submitted my PR application after 90 days from submitting the initial application for WP permit the IRCC rejected my application for PR. That is actually not true as yes the IRCC website states that you should submit your PR within 90 days from the original date of submitting the WP permit but they do not say they will strictly reject your application if they are submitted after 90 days. The letter I received from IRCC regarding my PR (as my application was returned) did not even mention that the application is rejected because it was submitted after "90 days frame time". Instead I was asked to provide some missing documentation, thats all. SO as long as the endorsement is valid they will process the PR. And why did I submitted after time ? - because there is a lot of information to take in about immigration process and that is how I understood it at the time. However before dismissal while I was still working I had to apply for extension of my work permit (as my passport was expiring) and alongside I also submitted my PR. After I sent both applications for PR and WP and the endorsement expired but as the employer found someone else at the time I was dismissed even though I was legally able to work. I did not check before applying for AIPP but now I know that in Canada while you on probation period the employer can just say bye bye to you with no apparent reason that what has happen to me. I made a complaint to the organisation that deals with employment law but was informed that they cannot do nothing about the unfair dismissal as that is the law but if I feel that I was unfairly dismissed and would like to claim my losses/damages I can file a claim (chargeable service) to small claims court. You see the immigration process is not always straight forward and sometimes applications will be returned to you in order to provide additional docs etc. and the employer must understand that they may be required to extend your endorsement which has only 6 months validity. If like in my case they dont the choice is to find another designated employer and start the AIPP all over again, go back home or if you have a partner they can get their employer to become designated and then you can start the new AIPP application but with your partner being the main applicatant.
What I would say is: If you have job offers ensure that you speak to your future designated employers about things like:are they actually willing to support you through the immigration process, you may even want to ask if they could include in the employment contract that they are happy to extend your endorsement if need be. I hope you find this info helpful and I wish you all the best in your applications. I put few links to give an idea
https://www.cfib-fcei.ca/en/tools-resources/new-brunswick-employment-standards
https://novascotia.ca/lae/employmentrights/endemployment.asp
https://www.princeedwardisland.ca/en/information/workforce-and-advanced-learning/employment-standards-pei
https://www.aesl.gov.nl.ca/publications/labour/labour_relations_work.pdf