Happy New Year to everybody!!!

My 1.5.1 Zen Cart is using custom templates.
I was staying away from modifying core files of Zen Cart knowing that they may be overwritten by new Releases.
Can I use Softaculous solely to update to 1.5.4?

I am guessing that many hours were invested in writing Softaculous Update Script.
There should be some use of it. Shouldn't?

Otherwise what is it developed for?

Thank you for your respond in advace.