A google search revealed that the surname Cavenagh is mentioned on page 44 of The Convert Rolls: The Calendar of the Convert Rolls, 1703-1838. There is no preview on Google Books. The Convert Rolls are available through JSTOR at Cambridge Core but I don't have access to that part of JSTOR. https://www.cambridge.org/core/login?ref=%2Fcore%2Fjournals%2Firish-historical-studies%2Farticle%2Fabs%2Fconvert-rolls-the-calendar-of-the-convert-rolls-17031838-edited-by-eileen-obyrne-with-annotated-list-of-converts-170378-by-wallace-clare-edited-by-anne-chamney-pp-xviii-487-dublin-irish-manuscripts-commission-2005-65%2FAB5A68DDDFE0F28835EB40FDA823106B#
My possibly relevant forebear is my 8th great grandfather Dennis Cavenagh (c. 1620 – after 1685). Dennis Cavenagh is named in two depositions associated with the County Kildare rebellion 1641, part of a collection held by Trinity College Dublin. In the church registers of Athy, County Kildare. Dennis Cavenagh’s son James was recorded as a Protestant. The attainder of his father perhaps gave rise to this change in religious affiliation.
The rolls may deal with a later period so my not be relevant to Dennis.
Wikitree link https://www.wikitree.com/wiki/Cavanagh-883