Nikki,
First, welcome to JDEList.
Second, We, because of a variety of factors, are using the PY environment for our development and have done so for a few years. However, we don't do a great amount of development work. I have had to modify the OMW rules as well. The discomfort is not that great, but I would prefer to have a separate development environment. The DV environment is still defined within Xe, but some of the schemas/owners do not exist in the database. The situation is the same for the JD or pristine environment. With our upcoming upgrade I am expecting to get all the environments (Pristine, Development, Training etc. or their 8.11 equivalents) back and in action.
That being said, I agree with Brother Of Karamazov, and do not recommend our situation. Especially if it is to be a temporary/interim solution. The data of the PY environment has become highly disorganised and refreshing it from PD could damage some of the developments in progress. We thus are limited to the testing we can do before puting any devlopment into production. We have not had any major catastrophes, only some relatively minor problems, but the risk is significantly greater.