Modern Doucai porcelain teacups health risks

[mhegara]

Hi everyone!
I've recently purchased a couple of teacups from xianyu, from a highly rated seller. The teacups are made in jingdezhen by a renowned studio "玖芝山房" (at least I think it is renowned based on my research and the high price of his work). the cup were listed for 4000cny and 3700 cny.
As I was blinded by the will of purchasing them, grasped by their artistic beauty, I overlooked the possible problems coming from the enamel painted surface (regarding heavy metals like lead and cadmium): one of them has the inside of the cup painted as well (where hot tea will be in contact with), while the one with cranes has plane white porcelain inside. I've contacted the seller through superbuy, asking for certificates that in some way can prove the safety of the cups, but his answer has only been "暴德镇窑口都没有这个的; 放心都是用原矿釉的": practically saying "trust me, they only use genuine enamel".
So my questions would be:
- Does anyone know the studio and can somewhat testify for the safety of their materials?
- in general, is it highly concerning to use modern doucai porcelain as my teacups if tea come in contact with the painted enamel?
- What can you advise to ease my concerns ?(chat gpt suggest to do an XRF analysis, but I'm unsure about the cost, its effectiveness and the possibility that the lab could damage my items). I'm delighted with my purchase but I mainly took them to use them: it would pretty dramatic for me to have to display them only!

Hopefully someone can come to the rescue. Thanks a lot for your invaluable help!!