The Lotus ECU is a very sophisticated 32 bit controller. I would imagine it is very capable of handling a turbo with the proper tuning. The reason people go with the piggybacks is bacause people have not been able to fully crack the ECU or because they have insufficient range. Or they convert the signals to work with injectors with different impedence or drive voltages.
If someone has experience with the Lotus ECU (TEC4?) then they should be able to program it, unless Lotus has encrypted the ECU code.
Just the opinion of someone without an engineering degree and enough knowledge to be dangerous
Greg