If the main concern is whales converting Steem to Curation Power there are numerous ways this can be throttled:

a. The total increase in Curation power (per account) can be capped down to 1% per day of the curation power already available (or alternatively awarded to) in that account.
b. Separately or in addition to (a.); the total steem, in the whole system, currently being converted to Curation power can be kept to say 0.05% of the total of curation rewards ever distributed.

And so on, and so on…