Regarding Multiple Prorate Convention in Tax Books

Hi

We have  a requirement to setup Tax books with the below asset categories

Computer Equipment :  5 yr MACRS Half year convention

Qualified Leasehold improvement : 15 Yr STL Half year convention

Non Qualified Leasehold improvement : 39 year STL Mid Month Convention

Below are the queries with regards to these setups

1. While setting up the asset categories , do we need to enter different  prorate convention & retirement convention as Half year , Half year , Mid-Month for above 3 respectively ?

2. To achieve Mid Month convention , do we need to implement a 24 period prorate calendar ?

3. In such case of 24 period prorate calendar , do we need to modify the seeded MACRS 5 Half year convention so that it contains 24 periods ?