Uninstaller size calculation

When I use the "WriteUninstaller" instruction, I also have to manually add the uninstaller size to the section, but the problem is that the size depends on the script contents; moreover, the size gradually changes while NSIS is improving (every day? 😉). Is it possible to calculate the uninstaller size automatically?

It'd require non-trivial source changes. It can not be determined when WriteUninstaller is processed but only after uninstall_generate() returns. That'd require remembering in which sections WriteUninstaller was called and how many times. Those sections should then be altered after uninstall_generate().