Especially since he also wants to make voting non-compulsory. That would make us more like the US, an electoral system nobody should copy.I think only systems that don't have full preferential voting are various upper chambers such as the Senate with a combination of partial preferential voting and proportional representation? Queensland doesn't have an upper chamber.
One benefit to moving away from full preferential voting is that it means more votes counted where a voter has a clear preference but has failed to fill in a ballot correctly. And as a general role more inclusive voting rules could be considered 'better' or 'fairer'.
But can't imagine it's an altruistic angle so there must be some benefit to the LNP in there somewhere... probably because of a lot of seats where Green votes flow to ALP or vice-versa to get over the LNP; if some of those Greens and ALP voters voted "1" for their party but didn't put a preference for the other ahead of LNP, that's a win for the LNP.
Equally true for any right-wing minor party preference flows into LNP... but realistically the Greens/ALP situation is the most significant source of meaningful preference flow in the country.