There is a specific rule requirement to disclose any possible disadvantages in the suitability report. The rule (COBS 9.4.7) can be seen here: http://fshandbook.info/FS/html/FCA/COBS/9/4.
Remember that a disadvantage is different to a risk. For example, there is a risk that investments can fall in value, whereas a disadvantage would be that the recommended product has higher charges than the product being replaced.



Reasons for recommending a transfer or switch that are open to challenge
Alistair MacDougall Compliance 2017, DB Pension, FCA, Pension, Pension Transfer, PI, Switch
CP19/25 highlighted some commonly used reasons to transfer/switch that often do not stand up to close scrutiny.