I will share a little information with you for what it's worth:
Based on what I've "heard" others say, this particular model Expy doesn't seem to have the best AC system. I say this because I have a 2008 Expy which I purchased NEW! Straight off the lot that very hot day in July 2008, I felt the AC should be able to do a little better. Since I have refrigerant, a manifold gauge set, vacuum pump, scales, etc., I decided the following summer to evacuate the system and refill. After the work, nothing seemed to change for the better.
This year, I noticed there was a little oil residue accumulating around the TXV valve. I went ahead and purchased and replaced the TXV valve and installed new "O" rings. I then vacuumed the system. I pulled the system down to 500 microns. With the vacuum pump off, the system then held for 30 minutes at 500 microns, so I knew there was no leak present. I weighed in the appropriate charge and the system is back to "ITS" normal. It cools and keeps the Expy comfortable but my 1998 Expy and 2015 Jeep do a better job.
At 93 degrees outside temperature, my 2008 Expy puts out approximately 50 degree air at the center vent. Pressures were 260/33 on the day I completed the work I mentioned above.
My 1998 EXPY easily puts out 40 degree air on a comparable day.
Hopefully, this info will help in some way!