Hello,
I just wanted to share my own experience with the installation of /e/OS on a Smartphone.
My first idea was to buy a refurbished phone. As I know well Xiaomi since long time ago, I selected a “Redmi Note 7 Pro” that was in the Smartphone Selector list page. When I received it, it was as if new in a nice packaging with screen protection, silicon case, power supply, USB cable, really nice. Unfortunately, when I placed my SIM card in it, I was unable to send and receive call even if the card was recognized ! Then, I was also unable to register the phone to my Xiaomi account, needed to unlock boot-loader.
So, I send back the phone and choose a LG because of the removable battery. But when I started to look at the /e/OS installation page, I picked a link to LG site, where to get code for boot-loader unlocking, I saw that LG gives no more code for his Smartphones ! So I stopped this order as it seems impossible to unlock the boot-loader.
Then, I decided to buy a “Xiaomi Redmi 8”. But when I received the phone, I had the exactly same problems that with the “Redmi Note 7 Pro” ! I tried another SIM in the phone, and it was working well for calls ! After long search on Internet, I found that this problem was known for those phones 
. I found a solution by placing a SD card beside the SIM card in the drawer. Then, always unable to register the phone in my Xiaomi account ! I decided to ask Xiaomi support to help registering the phone and then obtain the code for boot-loader unlocking. I was very disappointed when they answer to me a long mail saying that it is dangerous to install another OS on the phone, I will loose the warranty (over a 7 years old phone ?), and take risks of personal data expositions 
. So, they don’t want to help.
I know that there are software like “DroidKit” to unlock the phone. But I don’t want to pay 40€ to unlock a phone of 60€. Maybe it is possible to do it in a Smartphone shop… I don’t know if I will try.
After that, I decided to buy a refurbished phone with a good reputation regarding unlocking boot-loader. I found two brands : Google Pixels and OneNote. I found a little bit too much to put a Google-free OS on a Google phone, so I bought a “OneNote 7”.
Take apart that I had some trouble during the installation because I upgraded the phone at first to Android 12 (instead of Android 11). Finally, I was successes to install /e/OS over it, with the help of this community. Thank you again.
Conclusion : in my point of view, if you want to test /e/OS, be careful to choose the Smartphone. If it is a refurbished, be sure to be able to unlock the boot-loader because it is the biggest problem in this adventure.
Now, I am testing /e/OS on my new phone and, up to now, I am pretty enthusiast !