ILR English test & absence letter

Hi all, I am applying for my ILR (Tier2 general- 5 years route). I have a couple of questions. I have searched these topics in this group and found varying answers, I wanted to know how it suits to my situation
1) I had taken academic IELTS in March 2015, which I used for leave to enter the UK in Nov 2015. So, can I use the same for my ILR application for English language requirement?
2) I have worked with 2 employers, I have been with my current employer since 2018. 2015-2018 I was working for another company. So, should I have to get my 'letter of absence' from both companies with all the detailed dates of absence? Or just a cover letter by me for previous employer work n detailed HR letter from current employer would work? Also, is there a format for this letter?
Please help

1. If you start filling your ILR application (don't submit, just use as draft), then it will be clear if you can reuse that IELTS or not.

2. You need letter from previous employer as well.