Since others do have a question or concern about Ginebra should get another import as Brownlee is now a Filipino, this is my point of view.
Naturalized players are being pushed for the sake of playing in our Gilas team. It's not meant for PBA. As far as PBA rules are concerned, naturalized players are still considered as import therefore Justin Brownlee is still an import. Remember Marcus Douthit? He still plays as an import even as a naturalized player.
I remember that and I also have that same sentiment regarding to that concern, if PBA will allow Brownlee to play as local due to his new citizenship what team can stop them if another import will be added to their squad? come to think of possible lineup, CStand, Japeth, Scottie, JBL and the import..
Hahahaha..
Just imagine, if PBA imports will be eligible to play as a local when they are granted a Filipino citizen, it will bring unbalanced to the league which is currently unbalanced right now. Again, players like Brownlee are just being considered with a Filipino nationality because of one reason, to be able to play with our national team. The uncertain availability of Jordan Clarkson in PH's FIBA games is one of the reasons too that's why it was being pushed.
On the last note, if JC will choose to play, then JBL will give the space for him, right? Like what you mentioned, it's only a backup purpose in case JC is not available due to other schedules that may prevent him from playing in FIBA.