Problem with getting phones direct from Asia nowadays is you're gonna get taxed + customs at least in EU since the limit for importing without tax and customs is so low phones don't fit that limit. So at +25-30% price + shipping... may as well buy locally a Xiaomi etc. if you can't find Lenovo being sold.
You would have to be in a country where you can import and not get taxed up to a high limit to make buying phones from Asia sensible.
Done it before, would not do it again, not nowadays when these cheaper brands are everywhere in shops even the smaller ones can be found. Makes no sense to bother importing individually, potentially get scammed, have no warranty, deal with customs, etc.
Updating Android and rooting it is a royal pain especially on Chinese phones that use Mediatek, you're almost never gonna root it unless you speak Chinese and manage to find a tool that can and isn't riddled with viruses/etc. Getting official OS updates, forget it. Installing custom ROM? Yeah if you can root it and do all the regular advanced things, you can actually find or make a custom ROM yourself for that specific hardware, Chinese phones don't get custom ROMs, it's often the popular western sold big brands phones that do, ...
Lenovo is kind of mudding the waters, it's a big brand but some of their products are hard to find anymore in EU etc.
If we are talking a pure China made, Asia only sold phone, good luck doing anything with it, what you're gonna get is what you're gonna have. No root, no custom ROMs, and almost no chance to find tools to fiddle with it, no updates. But it can come with a clean Android unlike the big brands sold in west riddled with customized crappy UIs and other issues.
No headphone jack? Pass.
Removable battery? Yeah they stopped offering that on almost any phone years ago now. I still have one and it's an old Andoird now. They don't want people buying batteries and keeping phones for a long time ==> they don't release updates to make phones obsolete in software support and glue batteries into a glued shell so that you risk breaking things or need a ton of hassle to replace a stupid battery when on my phone it can be done in 15 seconds.