Should I upgrade my Intel E7600 CPU for an E8600 in my iMac 27" late 2009?

It all begun when my factory Seagate Barracuda started clicking. I knew the end was nigh for my beloved iMac 27" 10,1. I then watched some tutorials, did some research and realised I could do this and upgraded it with a fantastic OWC Mercury Electra 1 TB SSD kit. Results were great, honestly feels like a new computer. Addicting I would say. I had 8 GB of RAM and yesterday I maxed it out with four 4 GB Crucial DDR3 modules. I already had the best (for the time) option for the GPU so the only thing left (for staying in the official in-period specs) is to swap out my Intel Core 2 Duo 3,06 GHz (model E7600) for a Core 2 Duo 3,33 GHz (E8600): 3 MB cache vs 6 MB cache and around 10-15% gains in performance (maybe?). For a grand total of 25 € shipped. Honestly, I watched a couple videos and read the official Apple Technical Guide about removing the logic board and I feel I might be pushing my luck a little bit. Especially all those cables, I have this crunching feeling that I could snap something that sat there undisturbed for 13 years. And removing that infrared receiver behind the front Apple logo... simply scares me. But on the other hand, I could officially max out the specs for a 2009 machine! The thrills! The excitement! Not to mention giving a good cleaning inside, renew the thermal paste, change the CR2032 battery (what is it used for anyway?)... I cleaned what I could during the SSD surgery but there is room for more by removing *MOAR*. 1. First of all, I think I duly did my researches but this is a plug & play swap, right? No funny business like EPROM flashing or macOS patching. I also know i5 & i7 are not officially supported on my board. 2. Someone went down that route? Should I? Shouldn't I? I sort of see myself as a DIY guy and carried out various successful projects (on cars too) but I fear the unknown. 3. Are the perf gains actually noticeable like the SSD + RAM upgrades or am I just lying to myself and the only benefit will be knowing that I maxed out my machine by gleefully staring at the "About This Mac" window? 3. Words of caution? Advice? Should I just move on with my life instead of following this inane goal even if the idea of putting some more life in this iMac has been a great project during those last days and is pretty motivating? Cheers for *any* input!