I found temps of alcohol lab burners as high as 1100C listed on the web, but nothing I would say is good science. It depends on the flame pattern, transfer of heat out to the ends, contact with the pot, etc, etc. I would want to see a reading from a good thermocouple when it was sitting in the flame right next to the stake/pot.
Hikers have been doing the tent stake trick with alcohol stoves for quite a while. As others posted here, you may have issues with the uber light ones. I've used them with Esbit too, which is quite hot.
Keep in mind that the thin parts of 11,000 BTU Ti propane stoves are hanging right out in the the flame without melting. The tiny steel supports on the Zelph stoves survive as well.
Here is a 3mm 6.4g Ti stake that has been used for a pot support. You can see the colors.