Seems that my hunch is correct.
Mercurytech and monmart @ shoppee sells 'tampered' with sets. Well, since they need to flash roms, they have to open the set.
When I got my Lenovo pad pro 2020 from this seller at qoo10 (with a $100 coupon), it comes sealed with plastic wrap. Opened up and it comes with the official zui.
https://m.qoo10.sg/gmkt.inc/Mobile/Goods/Goods.aspx?goodscode=656685253&banner_no=1305330
This seller also carries the pad plus 2021 at $350. Chances are it will also be a sealed set plastic wrapped with untampered zui rom. Price is on the high side since qoo10 often release big coupons during weekends and sales.
So for all 4 models of Lenovo pad, these are my recommendations to avoid the complex qpst flashing to get to official ROM.
2020 pad/pad pro:
Any seller. Whether if it comes with unofficial ROM or cn ROM, it seems quite easy to go official global ROM with the official Lenovo tool. (Multiple success from folks here already)
2021 pad plus:
U can try to get from the above qoo10 seller, or safest go for tanteo785 and request for china ROM in the remarks section.
2021 pad pro:
Only get from tanteo785 and request for china ROM in remarks.