WITH_BMAKE: make: "/usr/ports/Mk/bsd.port.mk" line 5137: warning: using previous script for "-depends" defined here

Well, I'm brave and switched several "beta switches" on my FreeBSD
10.0-CUR systems on and I realize, that I receive a lot of

make: "/usr/ports/Mk/bsd.port.mk" line 5137: warning: using previous
script for "-depends" defined here
make: "/usr/ports/Mk/bsd.port.mk" line 5140: warning: duplicate script
for target "-depends" ignored

messages when doing updates with portmaster or installing ports.

I think this is "BETA-normal", but a re there serious implications apart
from some performance issues at the moment using bmake as the
replacement for the oldish make in FreeBSD?

I'm just curious, so feel free to answer if you like.

Oliver