Yes! The Magic toolbelt booster stacks with ANY of the regular boosters. - For example, if you have the Magic toolbelt booster and a regular 2X SWIFT FIXER, you can stack the 2x SWIFT FIXER with the Magic toolbelt 2X SWIFT FIXER to become a 4X SWIFT FIXER.
For regular BOOSTERS, while you can use different boosters simultaneously, you cannot use two of the same BOOSTERS to increase the power ups.
For example, you can use a GREASE LIGHTNING 2X and a SWIFT FIXER 3X at the same time. However, you can't use a RAIN MAKER 4% and a RAIN MAKER 6% together. The second BOOSTER you apply will override the initial BOOSTER.
For regular BOOSTERS, while you can use different boosters simultaneously, you cannot use two of the same BOOSTERS to increase the power ups.
For example, you can use a GREASE LIGHTNING 2X and a SWIFT FIXER 3X at the same time. However, you can't use a RAIN MAKER 4% and a RAIN MAKER 6% together. The second BOOSTER you apply will override the initial BOOSTER.