Soldered RAM is locked tight.

No.

Soldered RAM is physically attached to the motherboard and permanently set to whatever frequency and timings the manufacturer decided at the factory. There is no way to adjust it via BIOS, XMP, or any overclocking tool. The memory controller on the CPU talks directly to those fixed chips, and the system doesn’t give you options to change them.

Even if you could modify the firmware, the thermal and power delivery for soldered RAM is designed for that exact spec. Pushing it higher would probably cause instability or damage, and nobody bothers to support it because the target audience for soldered RAM (laptops, mini PCs, soldered-down boards) isn’t overclocking.

If you want overclockable RAM, buy desktop sticks in slots. Soldered is the opposite of that.