FI; What do you mean by "involuntarily transferred to FERS from CSRS"? Did you leave the federal government and redeem your pension and then go back later, in which case you had no option to choose CSRS? That is the only scenario under which you would "involuntarily" be in FERS.
At the time that the federal government "switched" from CSRS to FERS, current employees were given the "option" to convert to FERS, but it certainly was "opt in", not forced in any way. At the time that this happened, one of the selling points was portability. If you made the switch, the government started depositing to your TSP, which of course builds faster than the CSRS pension. Only those who knew they would be leaving the government would be incented to make the switch.
I can recall one person (only one) of very large number of people in our agency who voluntarily switched. He never did leave the agency and sorely regretted making the change.