manual install qnxbase.qfs partition size

If I was going to attempt a manual install (copy from PCI to non-PCI)

qnxbase.qfs

50 Megs (current Patch B size) for a boot (qnx4) partition does not
sound too bad. (small boot partition below 1024 cylinders)
(a little bigger than the recommended 16 Meg /boot for Linux)

But what is the expected growth of the base rtp ?

if base is t77, does root need to be t78 ?
Even if it is an extended partition ?