That's a kit with like 5 tools in it. Which are we talking about? The fork spring compressor?
YouTube
Seems legit. He says you "need" this. I've done several forks-cartridge and not-and not felt this 'need'.
Same guy uses an impact to remove the fork cap. So. Yeah. Not sure this is an expert to cite.
More parts of the internet seem to suggest trying to compress fork springs by hand is "dangerous" and a sure way to die. I feel otherwise.
It's awkward sometimes, but I've never had any problem compressing a fork spring by hand. Sometimes a gentle twist will hold it in place against something on the damper rod. Or grip the spring and the fork body together in one hand. Usually find a way.
I cut my own "spring hold-down tool" out of some scrap aluminum. (License plate, actually.) It is +10 man points because of the jagged edges and risk of cutting your hands.
On second thought I think I may have a stamped steel bit like in that traxion kit somewhere. Although it is just as likely that I'm either remembering things wrong or have lost it.
I have a motion pro oil level tool similar to the one in that kit. Awesome. Great to have. Not mandatory, but really handy.
The bleed tool seems gimicky. Definitely not mandatory. This attaches to the top of the damper rod and lets you work the air out? I've never had a problem just grabbing them by the threads. (That's what trump said!)
Or is this so you don't lose the damper rod down into the fork on re-assembly? I guess I could see value there.
A
socket set like this + an impact driver are your best friend for the damper-rod retainer. Gazillion other uses too. I have short and long versions in my tool chest.