Frozone was the original target for the Omnidroid v0.8 not Bob
It was intended for Frozone he was Syndrome’s original target as Mirage was originally staking out Frozone and just so happens to spot Bob with him. This causes Syndrome to change his target once Mirage confirms that they’ve located Bob. Syndrome had no clue where Bob prior to bowling night. Syndrome didn’t even know he married Helen Parr (example the database scene and the scene where he captured the entire family) the fight ended in the volcano originally because the robot was design to lead Frozone their since Frozone can’t use his abilities in dry air (example is the scene where Bob and Frozone save the people from the burning building and Frozone explains to Bob he can’t use his abilities due to the heat and dry air) Syndrome would know that to be his weakness since he was targeting him originally to begin with. Syndrome didn’t have time to adjust the program to Bob because he didn’t know anything about Bob’s weaknesses and was just banking on the Omnidroid to either finish the job or what ended up happening with Bob surviving and collecting the data to beat him. Which he did and that why couldn’t beat the upgraded Omnidroid because it knew at that point what Bob was capable of and did everything that prevented him from even getting close to the robot.
To support this theory even more:
Mirage finds Bob by circumstance due to Bob going out with Frozone that night. For Mirage to even know where and what Frozone is doing she would’ve scouted Frozone for a small period of time rather in person or through surveillance. When they were talking about Gazerbeam and listening to the scanner in the car. Mirage says “the fat one is still with him” she talking about Frozen being with Bob (unknown to her at the time) it wasn’t until after the escaped the jewelry store that she realizes that the “fat one” is Bob. That’s what makes Syndrome change course because Bob is THE target and they’ve finally spotted him. The environment conditions of the volcano is more advantageous against Frozone because Frozone can’t do anything in a volcanic environment Mr Incredible is not at a massive disadvantage in the volcano compared to Frozone. If Frozone would’ve originally been on the island (not Bob cause if Bob would’ve listened to Helen he wouldn’t had been spotted) then Frozone would’ve guaranteed been killed in the volcano because he wouldn’t have a fighting chance at all.
TL/DR: Frozone was originally supposed to be the target for Syndrome not Bob changing the entire course of the entire movie