The status of 'optimalization' as a word is inconclusive even though you can find it in Collin Dictionary and Oxford Dictionary. So I recommend you not use it by any means.
Even Google detects it as a misspelling.
Bryan A. Garner in Garner's Modern English Usage considered it a non-existent word.
optimize (= to make the best use of) is the word, not *optimalize[...]
LANGUAGE-CHANGE INDEX
*optimalize for optimize: Stage 1,†
Current ratio (optimized vs. *optimalized): 7,885:1† stage 1 means rejected
So if you want nominalize it, you must use the base "optimize" (NOT optimalize). So it should be "optimization."
