Block entity data in configured features

Does anyone know whether it is possible to specify block entity data for a particular block generated in a configured feature? I wish to have a feature that generates an auto true command block with a command, however, it seems you can only set block states in the block provider of every configured feature type. The closest I got was using the fossil configured feature which allows you to specify a template (which can be the command block I want). But the fossil, for no good reason, is placed with a random negative offset below ground, making it impossible to put it at the original location reliably.
Any ideas is much appreciated.