It took me a couple of matches to get comfortable using the wheel. And, as you witnessed, it becomes less effective if your partner has a quick tempo. Here's a few things I've done to adapt.
* I've gone to matches on my non-game days to practice using it. That has helped me get faster at using it.
* I keep my pencil in my front pocket, always open (I use bullet pencils), where I can reach it very quickly.
* I circle the setter, kinda dark so I can see at a glance where she's supposed to be.
* In a blank area of the card I write the setter and her opposite's numbers, as a fraction. So I don't have to "find" them on the wheel when I need a quick memory jog.
* I note subs on my wheel while I'm reporting them to the table. I don't give the court back until I've recorded them (I try not to slow my partner's tempo, but I've got work to do too).
* I don't erase subs when the original player returns. So I'm never writing a sub down more than once. I may pick up the wrong number the first time I glance at the card, but when I realize I'm seeing the wrong player, I know exactly where to glance back to on the card to pick up the right one.
* I draw a triangle in the pie slice where the libero serves. That's helped me catch the libero serving in multiple positions before. Many scorekeepers don't know about this rule and therefore can't help you out.
* Everything written after the game begins is kinda chicken scratch because I'm hurrying, but as long as I can make it out...
* Sometimes I have to wait a point or two before I have time to note something on my wheel, but there's always a 2-3 second break soon you can use
* I ask my scorekeeper before the game to be prepared to tell me who the next server is for either team. So if I'm suddenly unsure my wheel is up to date, I can quickly verify.
* I'll be danged if I don't consistently forget to advance my wheel whenever there's a side out and a sub at the same time. Grrrr
It's not perfect. But I'm a LOT better with it than without it. With use, some things have begun to click. With repetition I've learned where to expect to find the setter in each position. Now, instead of holding up the card searching the floor, the wheel reminds me of her position and I know where to look. It's starting to become automatic to pick up the number of the most obvious overlap when I get the setter's position. With this automaticity, now I have time to glance back at the wheel to pick up the number of the less obvious overlap. After a while the players that lead and follow the setter are committed to memory. That allows me, using the card and what the card has helped me commit to memory, to very quickly verify four of the six players' locations before the serve.
Next emphasis for me, I think, is tracking front row/back row better. I already keep track of my setter, and usually her opposite (if I haven't consciously noted the opposite's location, I at least recognize her and know she's opposite). So it should be a fairly straightforward leap to knowing whether her leader and follower are also FR/BR. Having said that, you watch...it'll take 3 more years to get that part
If a rally goes more than 2-3 points, the wheel is starting to go in my pocket as I know that alignment and don't need the card.
I expect I will eventually be able to track and recognize enough on my own that the wheel will spend most of the time in my pocket. Eventually I'll "get lazy" and stop bothering to fill in the lineup, since I'm not really using it. Then I'll stop carrying it altogether. Maybe that'll be this season, maybe not.
I wouldn't worry too much about what your P said, at least not today. He's right in that we shouldn't become utterly dependent on it. But why not use it to speed the process of no longer needing it.
Just my $0.025