[Yaffs] can GC happen on a file system mounted RO?

Related to the bit flip/ read disturb errors on MLC flash. It is
recommended to cause a GC to occur on that block. GC is checked during
writes, but on a Read Only File System this will not happen.
Can We just call the GC function on a periodic bases, even if the file
system is mounted RO?

Thanks

Chris G