Mostly everyone here is guessing. But, the best advice is to provide a quality of service and ask a customer to leave a review. You can incentivize with a discount or gifts. However, here's my take on your strategy:
Yes, having different laptops can work depending on the quality of email, the overall warming of the account, and how consistent you are with leaving human-like behavior over a month-to-month time period. Walmart Wifi has been used thousands of time(s) per day, with a wide array of usage. Therefore, Walmart wifi is not an issue. Based on my experience, a real Wi-Fi connection from a REAL device where Google knows where you are located is far better than proxies and VPN(s).
Review providers here love putting proxies on a pedestal, but most of their reviews are still being deleted and hidden by Google even with 4G-5G mobile proxies. So you have to wonder WHY EXACTLY? Because Google is factoring other account-level behaviors. Therefore, proxies or VPNs are not a core issue.
I've left reviews with proxies and VPNs turned on with my personal account and several other Gmail accounts (where reviews are LIVE by the way). To achieve this, it requires an unprecedented amount of human behavior on a real device. Quite honestly, it may not be worth the hassle, but there is a way to farm it.
But, just remember: any strategy that you come up with that requires a real device on a real IP address with real human behavior is better than 99.99% of what these fake review providers are doing. Take that into consideration and ignore them because none of what they are ACTUALLY DOING WORKS.
So, they are ALL full of shit.
Most of their reviews are being hidden simply because they do not control the quality of their emails, are heavily reliant on 3rd parties to purchase these emails and are spamming across the globe. Google knows these are not users that are valuable to their platform.