Not sure if the 10 overs would of helped as SL were able to bat the whole day and only lost 2 wickets. We don't know for sure as anything could of happened in them 10 overs but going by how SL were able to bat out a full day shows that it might of still ended in a draw or even a SL win. We got a fair idea that this would be a draw after the end of day 2, it seemed that both teams were playing for the draw at different stages of the match and even though the WI did declare as you said they batted for too long.
West Indies was happy with the draw and so does Sri Lanka and i thought Sri Lanka to start well and try to chase down the total at a good run rate and if they loose wickets then they should look for a draw as the pitch was not doing much and they could easily defend but they never tried winning and leveling the series which is unfortunate as the old Sri Lankan team would have went for the win first rather than a draw.
Srilankans were very clear about drawing the match from the very start, guess they didn't even think about chasing the target. 2 back to back draws seems boring in the modern times when teams are pushing for result. Was reading somewhere that its the first series after 2015 which ended up all draw games.