Sitebulb has a range of 'global settings' which act as the default settings for every new audit you start. From the Dashboard, choose the 'Settings' option from the left-hand menu.
From here, the 'Content' tab allows you to adjust the thresholds for how Page Titles, Meta Descriptions and H1s are classified in the On Page report. This relates to these specific Hints:
Simply overwrite any values you wish to change, then hit the green Save button to apply your changes. Note that this will not recalculate the data for existing audits, but the settings will come into play for all new audits.