While intended behaviour, this leads to the odd situation of being able to use a glyph and apparently "losing" it.

Using a glyph of higher tier than the spell book does work, but the glyph is hidden in the spell book's UI. It will become available when the book is updated.

To mitigate this, I suggest two fixes:

• A tooltip on Glyph Items indicating what spell books can make use of them
• Displaying glyphs of too high a tier as faded out and unclickable in the spell book's glyph list, with a tooltip indicating why the player cannot add the glyph to the spell bar.

For what it's worth, the glyph is actually recorded in the lower tier book; it just can't be added to a spell in that book's editor. Copying to a higher tier book or upgrading the book reveals the glyph.

This was partially addressed in 90d4723
Learned glyphs that were too high of a tier will display, with feedback to the player explaining why they cannot add the glyph to a spell.

Added tooltips to both, this looks mostly addressed.