Passed the PMI ACP and wanted to share my experience. I recently started a job as an agile product owner in software development using scrum, and have worked in similar roles in the past. 3 years of work experience. I had PMP from 2008.
Prep
PrepCast simulator - I did the simulator, learning mode with 40-50 questions each day for 30 days. Would review the answers after each wrong answer. I didn't take the full practice exam. Good use of time in quarantine. I ended up going through all 400+ questions at least once. Exam sim was harder than actual test but was close. You need to get repetition on the situations, what do you do as a product owner if x happens. Real exam was very heavy on the situations and light on the knowing the terms/memorization type questions.
Mike Griffiths PMI ACP book - Read through 2 times and took all the quizzes. This was worth getting.
Results said I was above target on all areas except one - adaptive planning. This was also my weakest area in the simulator as needed to remember PMI way vs how we do it at work.
Online Testing
I tested everything a few days before using their application. Then day before I removed everything from my workspace per their instructions so had a clean slate to start.
For check in, I took pictures of my work space and drivers license. Then used chat where the proctor confirmed everything was good. No phone call or long wait. Proctor was there right after I signed in.
Application for taking the exam was fine. You can't right click to cross out a question like you could in the simulator. The whiteboard was used only once for me to do some long division. If there was a calculator I missed it. The math was not that complicated so ended up not needing it.
After submitting the test, it flashed a screen that I passed. Then a short survey after. Then the app closed quickly. It did not give an exam report. I was only able to see the exam report 6 hours later on the site.
Overall the Online experience was great, follow the directions and you will be fine!