Hell, yes! Radical abolitionist anarchist libertarians can -- and I say ought to be -- incrementalists because, sorry, "abolition now!" is not on the menu today. No contradiction exists in the radical incrementalist or the incrementalist radical.
Tom Knapp addresses this point quite capably in his re-post "Blast from the Past -- Without a Net: Compromise versus Calculation." I recommend it highly.
The reason that no conflict need exist between abolitionism and incrementalism is that the former is an end while the latter is a means:
Incrementalism involves setting (and achieving) incremental goals -- taking "baby steps" in one's chosen direction. Incrementalism is a proposed means.
Abolitionism is the notion that wrongs should be abolished rather than simply minimized (and, at the abstract anarchist extreme -- no insult intended, that happens to be where I live myself -- that all wrongs must be abolished in order for the abolitionist to claim victory). Abolition is a proposed end or set of ends.
Thus, Knapp adds, "incrementalist means are not only available to "purists" and 'abolitionists,' but used by them, and are therefore not available only to 'pragmatists.'" He also has much to say about "pragmatists," who turn out to be pretty poor incrementalists.
I wrote about this issue five years ago in "Rothbardian Thoughts on Strategy."