ESA Migration notice

I have an ESA migration notice to UC, to claim by 9th September, just over a month away. I have gone through the relevant guides here. However, I have memory/concentration difficulties due to my disabilities. So I am finding it particularly problematic in interpreting and even starting this process as i have complex needs. I am also having quite invasive surgery at the end of this month and I am overwhelmed about that too.

I am currently in the ESA Support group , but get additional money because I am severely disabled and because of the Disability income guarantee. I am also getting Housing Benefit and Council Tax reduction. when I register for my UC account and submit the form , will these supplementary additions to my ESA , automatically transfer over to UC? I am confused, as I've read about "transitional protection", so I'm unsure if i need to apply for the supplementary additions (for being severely disabled and Disability income Guarantee) separately. Also , from what I understand "transitional protection" is only temporary.
Is it possible to continue receiving my current additional "top ups" in ESA when transferring to UC without a temporary status?

Finally, If I were to ask for an extension from deadline of submitting form, as I'm having surgery soon and for complex support needs . How long do extensions last for usually ? And will I continue remaining Status Quo regarding ESA etc if given extension? Thank you.

I have an ESA migration letter to submit form by the 9th September. From what I understand, "transitional protection" is a temporary replacement for the top up of severe Disability and Disability Income guarantee, is that correct? If so, it would mean that I am awarded less over time and worse off.