[Elecraft] Mildly confused - Assumed filter width and what I see in waterfall do not match

[Thomas Bingenheimer]

This is the current state of the radio :
the 6 khz filter is in FL2, the 2.7 khz filter is in FL3. ESSB is on, and set to 4.0, complete with the '+' displaying in the right of the display when USB/LSB is used (note that it is off during DATA modes). AM TX is set to FL2,  SSB TX is set to FL3 (it will not allow it to be set to FL2, even with ESSB on). IN data A, I am setting the DSP to 4 khz. If the firmware is enforcing the use of FL3 for Data A, why would this be so? With software that can do 4.0 khz or greater waterfalls, why would we want to arbitrarily restrict the radio? For that matter, why restrict it at all for DATA modes? If the software on the computer would do it, why should we not be able to receive or transmit with say, the FM filter? If there is any such restriction, I would like to have the possibility of removing it considered. Thanks!