Netbackup client installation on Solaris 10

Hi 

we have one client running at following OS.

SunOS prod_btp01 5.10 Generic_147440-16 sun4u sparc SUNW,SPARC-Enterprise

current version of Netbackup is "NetBackup-Solaris10 6.5.3".
we are planning to upgrade client to 7.6, as per my understnding it requires approx 2.5 GB space in /usr/openv and equal amount in /tmp for keeping temporary files.

now issue is we have only 1 Gb space in /tmp and it can't be incresead, /opt has almost 6 GB free space.

If I create a tmp dir inside /opt (eg. /opt/tmp) and pass this location for NB_TMPDIR variable and install netbackup in /opt (link to /usr/openv), will it make installation possible on this client ?