Bioequivalence and Bioavailability Forum

Dear All,
I would like to ask for your opinion in following case.
There are 3 strengths of BCS class I product X - 10, 20 and 40 mg. The reference product of 40 mg is not available in any EU country. All 3 strengths are available as generics of product X.
I have another generic company, which developed 10 and 20 mg and registered these strengths based on BE study on 20mg about 6 years ago. This BE study no longer fulfills current regulatory requirements (especially in regards to analytics) and probably would be rejected if submitted nowadays.
This company wants to add 40 mg to its portfolio. The following ways are considered:

1. Line extension to existing MA using biowaiver based on previous risky BE study (see above)
   
2. BCS based biowaiver: Test 40mg vs 2 tablets of available Reference 20 mg (at this moment it’s not sure whether dissolution profiles of reference 20mg are suitable for this).
   
3. BE study: Test 40mg vs 2 tablets of Reference 20 mg
   
4. Biowaiver for 40mg based on new BE study Test 20mg vs Reference 20mg

Are these options (3 and 4) doable from regulatory point of view? Which option would you go? Are there some other possible?
Many thanks in advance for your comments,
Best regards,
Luke