I did not have a clue what Dupuytren's Contracture was before I read this post, so I learned something new today. One thing that you might give some thought to is the glove with the pad in the palm will position the ball forward and more on your fingers. You did not say what your finger pitches are, but you may have more options  with reverse on the fingers if needed. The Ebonite Pro Form Positioner is another option for you. You still have the textured fore finger and little finger. It does have a metal plate on the backside, which can be removed if not needed for support. A good relaxed grip on your bowling ball should be key and a good glove for support where you need it for your hand.
jodyk24

[Update]  I purchased the Ebonite React/R Palm Pad Glove XL (Blue) and wore it in league. I decided to get rid of the palm cushion in this glove, I carefully cut the palm pad away because I felt it was in the wrong position and didn't cushion the palm in the proper position where my nodule cord condition is located.  Back in the 70's/80's I had the Don Carter glove (Mark Roth used to wear one) and the new Ebonite version is completely different.   The palm on the original sat more towards the fingers and was more in the pad of the hand (from memory) and the new Ebonite glove pad sits much lower, smaller pad, and sits towards the bottom of the outside of the palm.  I don't know if Ebonite thinks it is an improvement, it might be for some people, but just not for me.  I ditched the pad temporarily, but will experiment with moving the cushion pad to a different position or trying some padded medical tape once I have time to practice.

My feeling and impression is that the Ebonite glove (without the pad) helps my hand and gives me effortless grip because of the index and pinky finger grip material which relieves pressure in my hand.  So far so good, great relaxed grip on the ball with no stress or pain.  Ebonite makes three other versions of this glove with various gripping tackiness levels.  I ordered all of them to give them a try.

Ebonite React black (original) XXL,  React/Rx Red XL, Ultra Gripper XL (Dark Blue).
The only glove they make XXL is the original,  the XL React/R palm was pretty snug
but probably will expand/stretch given time. 
 

I hadn't considered wearing an accessory as being preventative.

Yes, it was a suggestion (orders) that my doctor gave me.  "Wear well padded grip gloves with any activity that would be deemed as stressful (to the hand)"  Bowling would be considered "stressful" in more than one way :>)

Basically, I am documenting my experience with the ailment so other's that might have the disease (est 10 million worldwide have Dupuytren’s) might be able to keep on bowling and enjoy this great sport.