I would also caution against buying an Android phone in China. Trying to get Google play services installed and operating can be difficult and might involve needing to install and unlocked bootloader and rooting the phone. I don't have any experience with Huawei phones. I've been using midrange Samsung phones, Galaxy A9, C9, etc for a while now. I made the mistake first time buying in China, in Shenzhen. I thought it would be easy to find someone in Huaqiang Bei to install the HK firmware, but I ended up having to do it myself. Since then I buy these kinds of phones in HK where the manufacturer usually has different firmware with all the Google services preloaded. Not sure about Huawei, but I assume they do a similar arrangement since they also market these phones internationally, except in the US.
For a premium phone, iPhone X(S/R), Galaxy S10, etc its still cheaper even with sales tax in the US. They only benefit for buying in China or HK is getting dual SIM. For iPhone, only XS Max and XR are offered with dual SIM. The iPhone price in HK is very close to US with sales tax, so the addition of dual SIM might make it more attractive. I believe most recent (past 2/3 years) Hauwei phone would work in the US but only with T-Mobile or possible AT&T, even then getting LTE (4g) may be hit or miss in your service area. Verizon generally only supports the phones that they sell.
Getting past the Great Firewall is another challenge. If you use a data roaming SIM card outside of China, you will bypass the firewall, no restrictions. If using WiFi or local SIM you are restricted and need a VPN. Last year there was a crack down on the VPNs and access became very difficult. It eased up a little then got bad again in early March, coinciding with the yearly central government meetings. I use ExpressVPN which is costly and advertises as best VPN for China. Last month it was not usable for close to a week, but slowly recovered service. I also have a SIM card from Hong Kong with data roaming across China, so I can bypass the restrictions using that.
With all that said, the new Huawei phones look real nice and I've considered one. Would just buy in in HK instead of China where it would also be cheaper. Sorry just realized my post here is a little US centric so take what you need and leave the rest.