While I’m no expert, I’ve read many places that its not necessarily about the number of reps, but about the time and what is being done with it.
As long as you aren’t squeezing too hard, going slowly is arguably better than going fast. You are much less likely to have accidents, much more in control of what is happening, and putting a lot less stress on the valves of your penis’s blood system.
Many of the more advanced routines that feature heavy jelqing usually tell you to focus on the time and not the count, because by the time you get to 600 who is counting to 100 6 times? I can barely do it once with my 2 year old without losing my mind.
Set a timer (like on your phone) for the amount of time taken to do the # of Jelq’s specified, and try to make each Jelq the length specified in your routine, usually 2-4 seconds When the timer goes off, move to whatever is next, even if it is your warm down. I usually don’t count the Jelq’s and just use a timer. If it says do 10 minutes of Jelqing 3-4 seconds each. Even if I don’t do exactly 100 jelq’s, and this time did 105 or 95 because you weren’t perfect with the “3 seconds per jelq”.. The end result will be largely the same, because gains are largely a product of time under strain. Getting those 5 more or oops doing 5 less and caring about the precision seems to me to be losing the bigger picture of what is actually going on.
Just be sure to see how long it takes you to do the quantity specified at least once. If it is way off, you may want to look at your technique, as you may be taking longer than expected to switch hands or have some other deficiency that is worth looking at. You can always use this new time as your future goal for this activity.