11 speed to 12 speed question

Help a non mechanic out. I’m toying with changing my Slice from 11 speed to 12. I have to put a new rear derailleur on anyway so might as well upgrade now if I’m going to. My question is do I need to update the front derailleur to a 12 speed specific? The compatibility charts tell me I need to but I don’t know if that is just Shimano trying to get more of my money or if there is a difference. Thanks in advance.

Yes you do need a new FD, assuming you’re talking di2.

I was curious about Mechanical
.

Is there mechanical 12 speed shimano time trial kit? Assuming there is then it will probably work but not optimally.

Is there mechanical 12 speed shimano time trial kit? Assuming there is then it will probably work but not optimally.

Don’t think anyone makes a road based 12 speed bar end shifters. Microshift makes a 12 speed bar end but its MTB pull ratio so you’d need a MTB RD unless you wanted to go friction shifting for the RD