I was planning on requesting CL increases and APR reductions from Amex, Chase and Citi but I don't want to trigger any additional hard pulls. I leased a car in April and have recently been shopping for a mortgage, so I have had about 6 inquiries in the past year. Any advice would be appreciated.
In my experience requesting a CLI would always be a hard inquiry. The entire purpose of showing an inquiry is for "new or increased credit".
In my experience requesting a lower interest rate has never resulted in a hard inquiry.
All you can really do is to rely on the anecdotal experiences posted by others for a given creditor, as the coding of inquiries as hard vs soft for consumer-initiated requests for new or extended credit is not regulated by the FCRA. Inquiry coding is an administrative creation of the CRAs to record type for future creditor reference and for credit scoring.