Yes Ryan Cragun is very good. Here is another he wrote:
Lawson also wrote an article decades ago demonstrating the differing trajectories of JWs and SDAs: SDAs have become a denomination of Christianity while JWs remain sectarian in character.
https://www.researchgate.net/publication/240592299_Sect-State_Relations_Accounting_for_the_Differing_Trajectories_of_Seventh-Day_Adventists_and_Jehovah's_Witnesses
Their work is a good counter to Rodney Stark who at one time argued both JWs and Mormons were on course become major world religions in this century.
https://www.tandfonline.com/doi/abs/10.1080/13537909708580796
I know all these artilces are not accessible, sorry.