Currently, team prefix and suffix is set using JSON in Minecraft 1.13, This allows teams to have longer prefixes and suffixes. The current limit is set to 32 chars but Team.setPrefix and setSuffix should allow for higher limits.

This will allow Scoreboard lines to be higher than 64 chars (including 2 chars per color used) and allows to not use any trick to cut strings (counting § char at position 31 or ChatColor.getLastColors) between the prefix and the suffix