Many Poles were quite Russian-friendly before 1830(and some even after that).
If Russian kept Poland is larger and more important, Russians might be more interested in keeping the status quo, that existed in Congress Poland-separate constitution, army etc. Might be reformed to Polish kingdom but with one of the Russian princes crowned as king, Polish nobles would accept such compromise.|
Also since Russia didn't wage large scale settlement attempts like Germany/Prussia did, there will be less Germans than OTL. Although some Germanization settlement already occurred after First partition
-Tsar's government breaking Poliand's constitution,
-General butthurt.
Kosciuszko was originally interested in working with Russian Tsar after Congress of Vienna but refused when he learned that Kingdom of Poland(that was the official name of Congress Poland) was to be smaller than Duchy of Warsaw. If Russia creates larger Kingdom of Poland after Congress of Vienna, than there will be less resentment-and more larger stronger Poland might led to more conciliatory moves by Russian state.