Knowing the rule up front is the key!
While a 4-way split is possible, I've seen 3-way splits a couple of times.
4-way example: 4 players hold an A; flop comes TJQ. All-in has 9/8. All 4 call, then comes a K. Four A-T straights, and one K-9 straight (out).
We have 2 bounty tournaments a year with two different rules. In one, we don't use bounty chips. If a bounty is split, both players get half credit. We track it by pen and paper. In the other, the rule is the first player to either put the player all-in, or the first player to call the all-in, wins the bounty. Since no split bounties are possible with that rule, we use a chip for a bounty chip in that tournament.
While I've never heard of the methods like a particular chip stack, or flipping cards later, as long as those are spelled out before the game starts, you can't call it unfair.
I used to play in a game where bounties were optional. They used a chip, but it got complicated when players split the bounty. They used 2 different chips -- a whole bounty and a 1/2 bounty. Then came a 3-way bounty. So if bounties can be split, a bounty chip is not that useful.
Like BG though, split bounties in our games are a rarity. I'm sure we'd have more if we did them more often, but with our bounty split rule, it has only come up 2 or maybe 3 times.