I've been running Unsealed Spellbook for the last 3 or so years. Here are (mostly QOL) changes I'd make to Unsealed Spellbook:
-Hotkeys to open the swap menu on either slot (like ctrl D/Ctrl F to open the menu on slot 1 or 2).
Hotkeys for each spell (alt 1-7 for quick swapping spells and avoiding the menu clunkiness altogether)
-Ability to ping when you're close to a spell swap. Unsealed Spellbook works best when your team is on the same page
-Hovering the rune panel reveals what time your next swap becomes available.
There is a clock icon on the HUD. But If you don't play with timestamps in chat/remember exact swap cooldowns you have to estimate it.
This change makes it easier to get into for people trying it out but Spellbook rewards you for knowing your swap times. I have mixed feelings about this one
-Fixed hexflash bugs/interactions or make the bugs official features instead. The 5 second swap to base cdr trick with hexflash is way too easy to do accidentally.
Prevent hexflash from overwriting your swaped spell when flash comes up.
The 3 Second cdr trick is the only way to not waste your swap. But it's technically bug abuse. You have to time it perfectly to use it though. So making these bugs features gives Spellbook a steeper curve
-Recent swaps are shown in a separate UI or rune panel rather than chat.
I like knowing when I can swap to the same spell again. But chat gets cluttered by the 9 other players unfortunate enough to be in my lobbies. Having to mute teammates or play without chat just to see swap history can be a disadvantage
-First swap 30 seconds earlier since minions meet 30 seconds earlier this season
First swap at 6:00 was balanced around minions meeting at 1:30 not 1:00. But this can make the rune broken again