Learn English – Pejorative form of flourish

Quality: Quality products. OK.

High quality products become: higher (or better) quality products or higher (or better) quality of product, lower quality products or lower quality of product, the best quality products or the best quality of product; the worst quality products or the worst quality of product; the lowest quality products or the lower quality of product.

That is how to do the comparative. This is just like the comparatives for words like expensive. Many adjectives with two or more syllables. That's how you do it.

for adjectives of three or more syllables: expensive, inexpensive, illustrious, crushing, etc. Those are just examples that would follow this pattern.

"Triggerer" has been a word for the past 60 years or so, according to Google nGrams. To my native English speaking ear, it sounds like a perfectly natural construction, but slightly awkward-- it's a word I could see myself actually using in an appropriate conversation, but despite the construction being natural, the double "-er" ending would feel strange on my tongue and I wouldn't like it. (I wouldn't like it, but I'd still use it and understand it perfectly well)

That said, it is definitely a word. In the context of computer programming, it is also likely to be the best possible word-- if you have a programming concept called a "trigger" with a defined technical meaning, then something that activates the "trigger" must be the "triggerer".

On the other hand, in prose or other non-programing contexts, I might want to avoid the double "-er" ending just for the sake of elegance. I wouldn't have to avoid it, but I might try anyway. Your suggestion of "activator" would be a fine choice in many situations.

But for programming, you can stick with "triggerer" for maximum clarity.