Given that MICROPAT (circa late 1980's) always was designed and developed to assess piloting aptitude against a general population background it would be perverse if BA were still using it as a selection tool for already experienced pilots.. Though they still might. Prof Dave Bartram who designed MICROPAT does now work for SHL so perhaps there has been a slight carry over.
If you passed your last LPC/OPC you have little to fear from the aptitude testing element. Worry about the interview or something else.
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