Custom tags with too long values make it impossible to edit existing custom tags via the GUI (see image below). Maybe easiest solution would be to truncate the value or have the overflow hidden?

Steps to reproduce:

• Edit landing page with a block with a editor
• Edit block and start working on rich text
• Create a custom tag with a text field with a long value
  • for example https://en.wikipedia.org/wiki/Lopado%C2%ADtemacho%C2%ADselacho%C2%ADgaleo%C2%ADkranio%C2%ADleipsano%C2%ADdrim%C2%ADhypo%C2%ADtrimmato%C2%ADsilphio%C2%ADkarabo%C2%ADmelito%C2%ADkatakechy%C2%ADmeno%C2%ADkichl%C2%ADepi%C2%ADkossypho%C2%ADphatto%C2%ADperister%C2%ADalektryon%C2%ADopte%C2%ADkephallio%C2%ADkigklo%C2%ADpeleio%C2%ADlagoio%C2%ADsiraio%C2%ADbaphe%C2%ADtragano%C2%ADpterygon
• Try editing tag
  • edit capability not visible