I have been working for BA dispatch for the past year, I can confirm that recruitment is only internal, and that 'operational' experience is required. My background is engineering, and I would have to say that a lack of check in experience did hold me back somewhat to begin with, but after a year it just about makes sense now. I have been with BA for a total of 12 years, with experience at two major hubs, both as a techie and manager before Dispatch.
We, unlike handling agents, are all load control trained, and we have to requalify for our load control licenses every six months in much the same way as flight crew with their sim checks.
Typically, one day in six is a load control shift, with the other five out on the ramp. The work is hugely varied, and this is really what attracts me to it..you really never know what the next flight will bring.
Are you in tomorrow older wiser, I'm on an L1
