Coordinate clause for two long sentences

Question

I recently asked a question about omission of auxiliary verbs in coordinate clauses. But I don't know I MUST omit the subject too or I can keep it, I mean:

These product items can be processed separately to extract the data fields from each of them (e.g. price, bids, supplier, etc.), or be displayed to the user for visual comparison.

vs.

These product items can be processed separately to extract the data fields from each of them (e.g. price, bids, supplier, etc.), or they can be displayed to the user for visual comparison.

Are both valid? or which is better?

Answer 1

They are both grammatical. The stylistic consideration has to do with how far the second verb is separated from the first. If there are "a lot" of intervening words, it's polite to remind the reader what the subject of both verbs is. But it's up to you to decide how many intervening words are too many.

• These items can be processed or displayed. (no danger of misinderstanding; repeating the subject is silly/superfluous)

• These items can be processed [blah blah blah] or be displayed. (a hint of parallelism: "be")

• These items can be processed [blah blah blah] and then [blah blah blah]; or they can be displayed [blah blah blah]. (pronoun refers reader back to "items")

• These [blah blah] items can be processed [blah blah blah] and then [blah blah blah]; or the items can be displayed [blah blah blah]. (explicitly repeats the subject))

You get to decide which way is most digestible for your intended audience.