Assuming the fusion boost's the same as in the Boo Arc...
R1: Gets past Golden Oozaru Goku. Gets stomped by anyone relevant to SS4 tier.
R2: Gets past Golden Oozaru Vegeta-Baby and 1st form Si Xing Long. Loses to Si's true form and Full Power SS4 Goku.
R3: Beats FP SS4 Goku as long as he's not hit by the 10x Kamehameha. Loses to post-10x Kamehameha Super #17, or Super #17 in general if he gets careless and gets hi Ki absorbed.
R4: Gets up to Yi Xing Long and whether or not he wins depends if SS3's strain is taken into account. Even if he wins, he gets stomped by Beyond Limits SS4 Goku.
If the fusion boost is nerfed to fit GT scaling, he should be far below Baby Arc Gotenks via scaling from Goten and Trunks' feats during the arc, so how far he gets depends on where you place Baby Arc Gotenks.