I've never really given much thought to staking plans. However, let's look at the following scenario:

1 ) Bet the fave for $1.
2 ) After a loss increase the bet by $1

Assume there are 4 successive losers and the fifth fave wins paying $2.00. The outlay has then been a total of $15 ($1, 2, 3, 4 and 5). The return is $10 which is a loss of $5.

With level stakes the outlay has been $5 for a return of $2 which is a loss of $3.

The loss with the staking plan by my calcs is 33%, whilst the loss with level stakes is 60%.

And if the winning fave paid $3, then it would be a break-even result with the staking plan but a loss of 40% (I think) with level stakes.

From this it would seem that the above staking plan might have merit. And even more so with Betfair where the fave has approx a break-even result for faves.

Just a thought...