The old PERL-RE made it possible to use \t to indicate tabs.
The new REINPLACE_CMD doesn't provide such a feature.
This is more a sed_inplace problem which I can't solve.
A patch would be to check all REINPLACE_CMD's for unsupported \-commands.
Try to build ports/devel/jam (the one dated July 11th)
Over to maintainer of sed_inplace
Unfortunately, this is the way POSIX regexp work, so that there is little
that can be done about that (see re_format(7) for details). Use USE_PERL if
you can't workaround the problem.