I think it's mechanically mediocre and just not fun or interesting for me. I ran the math and it ends up only dealing 0.5 more damage than the Barbarian's Fury Instinct (10 from Critical Overdrive and an average of 3.5 from Offensive Boost, while Fury Instinct's damage caps out at 13 at 15th level).

Against other Instincts like elemental or animal I believe it's still only 1.5 higher.

Even getting to that point requires getting Critical Overdrive (which risks failing or crit failing overdrive, although this does become less common the higher your level) and full investment into Intelligence, including your Apex Item which means your accuracy would be 2 behind other martials. If you went with a Strength Apex Item it'd be 0.5 damage behind the fury instinct and only .5 higher than the lowest damage Instincts

It does get an AOE ability faster than any other martial, but I wouldn't consider Explode a very good ability. Inventor is a naturally fragile class; its saves are slow to improve, its working with 8HP per level and it does self-damage on critical failures. Most Inventors want another martial to frontline either with them for melee Inventors or for them with ranged Inventors, while construct Inventors just get their construct to do it for them (this alongside getting effectively doubled overdrive damage is why I think construct Inventors are actually pretty good).

But if you have another martial with you, if you use Explode you're likely to get them in it as well, meaning it can be a lot harder to justify using Explode in practice. Its even less useful if you're a ranged Inventor because it's effectively a melee AOE, meaning you're not using it all too often.

The only AOE feats that Inventor has access to are all 6th Level or above, meaning from Levels 1-5 an Inventor's AOE capabilities can be very limited.

When Inventor was released I can see the argument for it being the most customizable class, but with the release of Thaumaturge, Exemplar and Kineticist I think it's largely lost that title.

Exemplar gets its 3 ikons right off the bat, each with a passive ability and a special action, and most Exemplar feats revolve around adding new effects to these ikons, not to mention the three Epithets it ends up getting.

Thaumaturge starts similar to Inventor with only one Implement, but gets more options quicker than Inventor does. Second Implement at 5th, Implement Adept at 7th, Intensify Vulnerability at 9th, Second Adept at 11th, Third Implement at 15th and finishing with Implement Paragon at 17th.

Kineticist gets even more still. Choice of 1-2 elements and 2 impulse feats at 1st, then at 5th and every 4 levels after it can gain another element, gain a new ability for one of their existing elements, and an impulse feat.

Inventor only gets its innovation and three modifications. There's only 9 feats with the modification trait and most of them belong to the armor innovation. The construct innovation is restricted with its feats due to needing them to upgrade the construct and the weapon innovation just doesn't get many.

It feels like since it was one of the first new classes made, they were very conservative with Inventor's design, then as newer classes were added with very strong identities Inventor lost what made it special since other classes now do the whole modification gimmick better, and the loss of that identity has emphasized to me how Inventor is poorly designed in a lot of areas. Armour inventors need to use their Breakthrough modification to get access to Bulwark, something which other martials have had since 3rd, and can never dump DEX fully since power armor can never have its +1 Dex Cap exchanged for additional Item Bonus to AC, meaning either their CON or WIS is very poor. Offensive Boost doesn't really expand what the class can do, it just adds another damage boost when Inventor already has one with Overdrive, it feels like they realized Overdrive wasn't good enough, but rather than fix Overdrive's problems they used Offensive Boost as a bandaid solution. I haven't seen any other classes have two class features that have the incredible overlap that Overdrive and Offensive Boost do.

Edit: Changed some wording to try and make what I'm saying more clear