The bgvp m2 looks quite good actually.. But when I searched for this model on aliexpress, I see 3rd party sellers listing the exact same model with Bluetooth 5.2, but bgvp official store says 5.1... Wonder why does every single 3rd party seller listing this at 5.2!
Sometime it is hardware related, but sometime it is software(firmware) related.
QCC5125, as listed by Qualcomm, is so far the only QCC512x series that is BT5.1. However, QCC5121 and QCC5124 (*the one in Qudelix 5K) are technically a more powerful SoC.and yet they are BT5.0 for now. We have seen in the past that Qualcomm can upgrade an older BT chip to newer BT version by firmware, so it is possible that we will also see QCC5121 / 5124 getting BT5.1 as well. As for BT5.2 - it is technically still not available in the market - if I recalled correctly, the schedule time to start rolling out BT5.2 is 2022. Qualcomm currently only lists QCC514x series as 'BT5.2 compatible' though those chips are not actually released yet.
On the other hand, going from BT5.0 to BT5.1 actually is a very minor upgrade as the only thing that seems to be difference is that BT5.1 can offer a faster pairing process, which means there really won't be any benefit audio wise going from BT5.0 to BT5.1. Going to BT5.2 is however the major upgrade as we will see a 50% increase in bandwidth, which will make for a strong connection as well as possible better HD codec, or even HD codec for TWS setup. However, we are still a bit distance away from BT5.2 and there is no actual BT chips in the market that is truly BT5.2.