I was thinking about that, the best US option forward is to sign big, long-term contracts at discounted prices to supply Oppo, Xiaomi, Vivo, etc... with premium parts hoping they can compete with Huawei in China's market to deprive Huawei of some of the revenue it needs to sustain its R&D. If that happens, then these Chinese companies would become vessels for selling US parts to the Chinese market in competition with China's indigenization efforts.
These companies need to resist that temptation and start moving in the direction of self-sufficiency, and hopefully, they can team up with Huawei to support the build-up of Chinese components because if they don't, they will essentially become foreign agents. If that happens, China's government needs to instruct them on the correct path or find a way to shut them down if they do not follow it.
Its kind of a problem since Oppo and Vivo has some kind of lawsuit with Qualcomm, but the lawsuit doesn't produce emnity enough to stop Qualcomm from supplying Oppo and Vivo with their chips (although one can say business is still business.) But Oppo and Vivo do tend to push their Mediatek devices first and foremost, and Xiaomi also has Mediatek devices. The low and midrange is the biggest volume for these brands and that is where these Mediatek devices reside. These companies do have low end to mid end Qualcomm devices though.
Team up with Huawei? Didn't Huawei refuse to sell HiSilicon SOCs to them? Huawei is not completely a saint here nor a patriot, although one can argue that they made Kirin exclusively for their own phones. You want to make the Chinese smartphone industry as a whole weened off from foreign parts, you need HiSilicon to be independent so they can serve the other makers without suspicion of bias.