[Pretty Chick]

If anyone has grown this particular variety of tomato, from experience, should I reduce the number of fruits per truss to enable the tomatoes to grow bigger?

Many thanks in advance 

[Trillium]

Some people do if they're regular on their plant feeding schedules. Others don't bother as they want quantity and are happy with whatever they get. You'll want to keep the suckers pinched out, the stems between the main stem and side branches as that saps a lot of energy from the fruit.

[8doubles]

I have never needed to thin the flowers with big-boy as there were never a lot to thin .
You could do your own `trial' and thin one plant to see how it compares with an unthinned one.

[Pretty Chick]

Thanks for the tips and I'll let you know my results