I would like to have everyone being invulnerable after spawning during the time you can spawn on the server (1st 59 seconds or what was it?) + 30 seconds more to be able to walk safely towards his teammates without being ganked by cav. If you leave a certain area this time of invulnerability is set to 0, to prevent spawnrusher cav or benefiting from this.
It's sad that I think such a suggestion would make sense with the current state of matters on the servers, but I want to point out that it is not only meant to protect people who needed to download the map, or with different good reasons for spawning lately, it's mainly because I grudge cav those easy kills. I think everyone should work for his kills, and picking off AFKers and ganking people who spawned lately with 3+ cav is definitely something wrong.
Or make everyone spawn at the same time. Cav spawning a bit later wouldn't hurt, imho.