There are several examples on stack overflow of how to enable/disable the debug perspective from opening when the debugger activates (i.e., hits a breakpoin
I found a simple workaround that obtains the same result. I now use the "Debug" perspective itself as my main perspective. I've customized the "Debug" perspective to look like the custom perspective I used to use. Now this perspective is the only one that is ever open and I can keep the IDE looking like how I want it to look.