The boards in postscript are way too overwhelming..

[PhantomRise]

Let me just say that this game has rapidly become one of, if not my all-time favorite since I started playing it a few weeks ago. The sheer amount of content is incredible! It's the gift that keeps on giving.

The ton of content hasn't felt overwhelming or burdensome; that is, until I got to the postscript and boards system. I love that it's giving me more reasons to continue enjoying the game and it's even making my favorite old/early gear viable again. But I simply cannot for the life of me remember "okay, [this weapon] changes [this skill] to this and [this Karon magic] to that and has [these affixes] but [this shield] also gives me [this new spell] and [these buffs], which would come in handy in [this area] but detrimental elsewhere..."

It's just way too much. Literally most of my gameplay time has now become inventory management, more than just playing the game.

[Nyu]

just dont use these boards. or choose the other of the 2 options on the board.

do you really switch your weapons so often that it matters?

[VertVentus]

Unfortunately, you'd have to look up the JP wiki for what the Possession skills change to, which drastically changes their application: how it attacks (sometimes for better or worse), if it changes into a buff, or if it changes into a follower (these aren't so great since they despawn every floor in the final dungeon).
The ones I liked are Lollipop > Magic Broom (MGC buff) and Angel > Regeneration (quick HP regen).

This guide does explain what each of the Karon skills change to,
https://steamcommunity.com/sharedfiles/filedetails/?id=2889115638
and the ones I liked are Junkie, Enhanced Barrier, Break Bash, Sumo Charge, Block Charge, Sustained Enhancement, Enhanced Guard, Counter Guard, Infinite Unlocking, Shuffling, and most importantly Command Claw (huge additional magic damage when equipped Katar, Mistileteinn, Seraphim, Beast Claws).

Boards equalizes the offensive/defensive stats of every single piece of gear so they're all equally viable, so you should instead decide which specific weapon you want to main and try to get all 6 elements on it (1~2 per 3 boards, 1 via gem), while considering what Karon skill it yields. Staves get a massive Weight penalty for a 0 Attack increase while knives/swords/spears can't use Shadow Spear while up tilting attacks for faster DPS, so it kinda boils down to hammers or claws.
For your shield and armor, the Karon ability they give is important. Otherwise, ailment resistance, guard value, max ST, and magical power. Anastasia (Maxwell) and Nexagram (Energy Drain) or Dewprism and Dark Witch's Dress fit either bill.
The enhancement system lets you convert your excess materials into stat enhancements to bolster them until you get boards on them, so you don't need to bother changing your equipment at all in Postscript, especially if you clear the arena early for the KEIZO Emblem to favor board drops on your current equipment. [Demon Rage + Full Burst + Darkness] Karon skills + [Berserk + Sylphid] Possession skills trivializes it. You'll probably need to externally keep track of which piece of equipment has what skill so you don't accidentally remove it though.

Thankfully, Gaiden streamlined boards for its dual job system for just stat increases.

[johnsonclint]

It is overwhelming at first, yes. :-)

As VertVentus said, utilize the Keizo Emblem from the Arena. I, too was overwhelmed at first. Then I just kept on my highest gear to get boards for the equipment I wanted.

Next, just know that you can choose to keep a board, or not. After you see a bunch of them you start to recognize patterns. To keep it simple, I would prioritize HP and Attack. After that, there were a few skill upgrades that I liked. For example, Pumpkin Bomb did a TON of damage.

In the end, there were only a few pieces of equipment I cared about. If a board looked "better" I would keep/swap. If it looked like it sucked, I would just move on. Just keeping it simple and prioritizing a few things really helped with the final bosses.

Just keep playing! :-) You will start to see patterns and understand enough to the point that it won't be overwhelming anymore.