I can't not imagine not having a central station sequencer
Mine is 30 years old, homebrew. There are 2 steps:
A) Receive to Transmit -> Everything hooked to "step 1" keys (receiver mutes, ants switch from Rcv to xmt, etc) 200ms later, everything hooked to "step 2" keys (rigs go into transmit, etc.)
B) Transmit to Receive -> Everything hooked to "step 2", above unkeys (rigs are put into standby, HV supplies unkey, etc) 400ms later, everything hooked to "step 1", above unkeys (receivers are unmuted, ant switches to receivers, etc)
Any other sequencing which may be required is part of individual transmitters, since this varies quite a bit with each unit.
The circuit consists of discrete transistors, R/C time constants, a power supply and some relays. The sequencer has 4 outputs: 120VAC and 24VDC for "step 1" circuits, and the same for "step 2" circuits. I run 4 conductor wire all over the shack, with 1 pair hooked to "step 1" and the other pair hooked to "step 2" (all 120V these days, but I used to use 24VDC way back when for lots of relays in the shack).
It is one of the most reliable pieces of equipment in the station - I have never done anything to it in over 30 years other than build it!
You could probably whip it up in a couple of hours from junk box parts, assuming you had an old rack mount chassis lying around and didn't have to do any metalwork. Mine is built into something that came off the scrap pile when I was in college (wow, that makes it close to 40 years old!!! - good thing I'm not getting older
)
Regards,
Steve