This winter I also tore into my carbs and used the low cost kits from Japan. With the same choke plunger without the guide pin. The factory ones with the pins are almost impossible to find.
So far, I have been able to make the bike run lean to brown on the plugs with no choke problems. When I installed the new kits a couple of months ago, I also was concerned about the deck height of the plunger and by not having the guide pins.
In the end, my choke operates fine, and does not seem to make the bike run rich.
One way to tell. After some use, the choke pistons should have a wear pattern on the bottom of the neoprene rubber cap. If there is no ring, or an uneven wear ring, then I think that would indicate that the plunger is not being fully seated into the boss at the bottom of the choke bore.
So far these non OEM plungers seem to be working fine on my end.
For the cost, I think the low cost kits from Japan are better than the Keyster Kits. The last time I used the Keyster Kits, the Jet Needles gave me some problems and there were no adjustment groves on the needle.
Hope this helps.
Todd.