As described in https://openfoam.com/documentation/user-guide/controlDict.php I can use
writeControl timeStep writeInterval 1 purgeWrite 10
to keep the last ten timesteps while purging older ones. On the other hand I can use
writeControl runTime writeInterval 0.1
purgeWrite) to get a permanent output of every 100ms simulated time. But is there any way to combine this, i.e. temporarily keep the last ten timesteps while permanently keeping the 100ms outputs? Especially for complex simulations it would be nice to directly identify the culprit of a divergence without having to resume from the last output time which might be minutes if not hours of real time ago, while keeping all timesteps and filtering afterwards also doesn't sound good...