Switching BLE on/off and get additional 29KB into heap

Worked a bit on a switch for BLE.
To be prepared for surprises, the idea is to calculate available jsVars.
Assumptions are:

• heap of 50000 bytes is sufficient
  
• use steps of 100
  

• maximum no. of JsVars is 20000
  Do you guys agree ?

  int heapVars;
  
  heapVars = (esp_get_free_heap_size() - 50000) / 16;
  heapVars = heapVars - heapVars % 100;
  if(heapVars > 20000) heapVars = 20000;
  jsVarsSize = heapVars;
  
  jsvInit();
  

One more question could we do something like
Bluetooth = nothing;
NRF = nothing;

or with a new (empty) object called isDisabled
Bluetooth = new(isDisabled());
NRF = new(isDisabled());