Timing Of 'Wages/Salary' Increase During Financial Year And Its Effect On Starting Savings Rate

HUMBUG

Apologies before I raise my question as I find tax matters and terminology very difficult to grasp.

Currently the only income I currently receive is from my ex-company pension , interest on non-isa saving accounts and dividends on my ex-company shares (via sharesave scheme).

My company pension will be £10.5k after the 6th April 23, but lets assume it will go up to 11k after 6th April 24.

However, I will get my state pension in Oct'24 which will be about £159 pw (£8268 pa).

My question:
If I have some 2 year fixed rate saving bonds (outside ISA wrapper) that will mature after
6th April 24 and before Oct'24 (ie. before I get my state pension) how will HMRC estimate my starting savings rate for the financial year from 6th April 24 to 6th April 25?  I'm just trying to figure out whether any interest I earn on the maturing bonds will be liable for tax at the basic rate.

I am assuming they will do the following:
1. Revise my yearly wages/salary amount to be:  11k +  'State Pension from Oct'24-6th April 25'  = 11k + 4.134k (approximately  six months) = £15134 .  
2. For every £1 over and above the 12570 personal allowance (nil rate) , reduce my starting saving rate =5000 - (15134-12570) =  5000 -2564 = £2436

Am I correct that I would be able to earn interest on any non ISA bonds maturing during financial year 6th April 24 - 6th April 25  up to £2436  without incurring any tax?  I suspect I can also add the £1000 personal savings allowance which may mean I could earn up to £3436 interest tax free (dividend nil rate allowance would be separate at £1000).

Note : Doing the calculations above, I am making the assumption that the government will not be changing the personal savings allowance, the nil rate dividend allowance & nil rate starting savings rate during the financial year 24/25.