While thinking about device layout, remembered interesting idea about temperature measurement. MCH heaters use wolfram film routes inside ceramic. Wolfram has big TCR, about 60% per 100C. So, we can use heater's resistance to measure temperature precise enough, without any additional sensor. The same method is used in vape mods with temperature control.

If no need to mount sensor, that extends the list of available components. Try to search "LED Remover Heating Plate" on AliExpress. You will see nice interesting plates like this one. I don't know how good are those (temperature gradient and cooling speed), but worth to try. Unfortunately, those alu-coated plates are 220/110 volts only.

I need to decide, does it worth continue with USB-PD, or switch back to AC. Bellow are summary of differences.

Differences between USB-PD and AC powered micro table approaches

• Safe.
• Compact.
• Can be done without case at all.
• More difficult to develop
• More easy to use touch screen

AC powered (with alu-coated MCH):

• Small size possible only without galvanic isolation, power switch, and with AC cable directly wired to PCB (without connector).
• 3D-printed case become mandatory for safe use.
• May be, more big size of useable surface (not tested yet)
• May be, more easy mounting (without aluminium foil and SS wire)
• No touch screen. Ordinary display + encoder.
• More easy to finish development

For AC, resistance control can be done with "energy meter" chips (BL0937, HLW8012).

What's next

I've ordered "aluminium heater", referred above, and wish to test it before moving forward. Hope this to happen in 2-3 weeks.

Let me know what do you think. I'm sorry, if USP-PD is critical for someone. But i hope any planned changes will do project better - still very small, but more simple,  and so on.