If a WO becomes commissioned and, after some time, cannot make another promotion, is there an option to go back to being a WO?

I would venture into thinking said individual did not pass WOCS (i.e. APFT, etc...) or somehow not finish WOBC. A WO1 isn't a commissioned officer until they are promoted to CW2 which is automatic after two years to the day they pin WO1.

No, as someone pointed out, you reach up or out after two looks. You can't go back to WO1, it's an appointed rank. All that you can do is resign your commission and return to you NCO rank, or join a different commissioning program that may require changing your rank.

Not sure about your scenario. However - I have seen a CPT resign his commission, become a WO and make it to CW3...then submitted a packet to return to the regular officer ranks...it was approved and he came back in as a CPT and got promoted to MAJ shortly after. Doubt that happens very often.

I would say that it's technically possible, but highly unlikely. Once someone leaves the WO ranks to become a Commissioned Officer, they'd have to apply to move back to become a WO. And, if their service record did not merit promotion as a Commissioned Officer, they probably are not competitive to become a Warrant Officer again. The Army doesn't have mechanisms to make it easy to "revert back whenever your promotions stall".

I suspect that such an individual is a prime candidate for involuntary separation. He is unlikely to be reinstated into the Warrant ranks.

SGT (Join to see) your question is confusing. Warrants are commissioned officers at CW2. Are you asking if they were to seek a commission as a LT, what would happen if they got passed over somewhere there after?

In the navy, if you reach retirement requirement as an LDO officer, you don’t meet you ten year requirement for your commission, and you want to resign your commission, they let you retire as one rank higher than the enlisted rank you commissioned at. If you aren’t at your 20 years yet, you go back to your previous enlisted rank.
Don’t know if this is a similar situation.

I know officers who became warrant officers. So the short answer is yes.

I know some people have done it to extend service. they did 20+ and are just making retirement points as a warrant ( reason was mrd)