It may or may not be true that the holy souls in purgatory are closer to the beatific vision than you or I, we will not know until we (hopefully) arrive there. Some stay in purgatory much longer than others. It’s possible that you will arrive and be released from purgatory much more quickly than someone who has been there already for a very long time and who may stay longer still after you have been released. As to the strength of their prayers, that’s up to God again. Such as is illustrated in the Gospel of Matthew 20:1-16, which was recently read a few Sundays ago. God’s mercy is parceled out according to His generosity, which is beyond our comprehension.
I tend to ascribe to the view of Saint Thomas Aquinas on whether or not the holy souls are able to pray for us, but this is not the only view on the subject. One can believe that the souls have the power to intercede for us, but it seems to me their state is a poor one. Although they are assured of heaven, and know they will not receive eternal punishment in hell, their suffering should never be trivialized. Their suffering is severe, they need our prayers. Personally I would not want to burden them with my concerns. I have every hope though that my prayers for them will be remembered and rewarded by their own prayers once they are released from the terrible suffering of purgatory.
It seems a new kind of ideology to be glad to find oneself in purgatory. We can not forget the suffering to be had there is severe, although unlike hell it is temporary.