After playing with the new wand progress system I noticed two major problems:
1. The system discourages player from having multiple wands. Even if a player wants just two wands for different occasions, they will have to do all the grinding twice AND find the appropriate upgrade books. Less wands makes gameplay less diverse in my opinion.
2. The system HEAVILY punishes player for loosing their wand. Not only player must find all upgrade books for the new wand, but they also have to do all the tedious grinding each time they lose their wand in a battle or magma-accident. Grinding for the same thing the same way every single time isn't a perfect gameplay experince.

As alternative solution I suggest removing progress bar from wands and adding it to the Arcane Workbench instead. Having one progress for all the wands would get rid of the first problem. And since it's much harder to lose a stationary block, then an item, it would eliminate the second problem as well. Players won't have to make all the progress from scratch, so an overall effect on the gameplay would be positive, even if you adjust the progress to require more castings for each tier.
Technicaly it shouldn't be hard to implement - for example each time a player charges their wand in an AW, the AW is moving closer to the next tier. This would direcly connect spell casting to player's progress in the mod.
And you can even add new fancy textures for different AW tiers! :D

That's an interesting idea, though linking progress to charging wands means players can just mine a ton of magic crystals, craft an entire stack of novice wands and then go through charging each one to full to progress. I like the idea of the workbench getting fancy textures for each tier though.

The new progression system was partly intended to discourage having multiple wands, or at least to make players work for them. Previously, people carried loads of wands with them, which made mana capacity and portable recharging methods kind of irrelevant. I do appreciate it gets a bit grindy, so there may be ways to improve that, I certainly don't think the system is perfect.

With the wand loss problem, I'll say what I've said to a number of people previously: if you spend ages getting the perfect enchanted sword/armour, or filling in a map, or exploring for a really rare loot item, losing that is no different to losing a wand. This is why gravestone mods and the keepInventory gamerule are a thing. Losing items that you invested a lot of effort in is a problem that's not confined to wizardry, so it's not really up to me to solve it.

Hopefully that makes sense, I'm not saying the progression system doesn't need improving (it does) but it should be improved to make progressing more fun and less of a grind, not because people drop their wands in lava.