Hi Octane a.k.a Hi Octane Blending Component (H.O.B.C) is merely supposed to be used as a mixture in most cars and will slightly improve mileage, fuel economy if the engine has a high compression ratio that specially or specifically requires that high research octane number. In my opinion there is no need for a 100% HOBC use in a GLi but mixing 50% or 40% or 20% ratio will be suggested for smooth driving. But if you have a heavy foot nothing will change and fuel economy nor ratio wont matter.
In short there is no need for 100% refilling in your case, but no matter you can try and see if it suits you. I personally used and tried it and got no better results in my Axio X-Grade CVT 2007 (1NZFE) and Altis 1.6 2015 A/T (1ZRFE) in the city and highway with 100% HOBC, but on the highway mixing 20 to 40% of it increased mileage by 1-2km/l but was slightly heavy on the pocket.
GLi (2NZFE) requires Regular / Normal Petrol and mixing HOBC "may" help, but not on 100% HOBC. The rest depends on your patience and deep pockets.