Just did mine today. It was a used stand I found online, but still the Triumph part. Ended up doing it the same way you did. Took the muffler off which did make more room to attach the spring. Then looped a zip tie around the end of the spring and pulled it through the hole in the stand with what looks like the same pair of channel locks as yours.
This is the way! I just put my stand on and there is no way to cheat this. Take the extra few minutes, do it like this and the whole job will be less than half an hour. The springs were not as bad as thought either. I zip tied my stand in the up position, grabbed the springs one at a time with vise grips, and they went right on without any struggling what-so-ever. Thanks for this video.
Installing the OEM center stand was one of the first modifications I did to my '22 Bonneville T120. I few months later I completely removed the awkwardly placed peashooter mufflers and catalytic converter. I've been riding it "straight-piped" regularly for about 18 months now.
What a PIA. I think the T100 exhaust likely does not interfere. Consider installing bumper after spring attached to slightly reduce distance needed to pull spring, then raise bike on stand and install bumper. I'll know soon enough. I'll be installing the TEC version on a T100 in the next few day.