PIP home med. assessment-delay?

Hello.
Five months after submitting my application, I've been contacted (yesterday, by text) for a f2f home assessment. I was a bit surprised as I didn't request a home visit. I did mention stairs can be an issue but I have to negotiate stairs when I go out, so it isn't a deal breaker regarding an appointment at the assess. centre.
I'm not sure if I should rearrange as the friend who was going to be present for the med. assessment may not be able to make it due to family matters. I don't really want to be assessed on my own as I feel it is better to have a witness present. I'll record it if I can. If I remember correctly, they don't have to give much notice for home visits. Just not sure if it is to my benefit to have someone come here. What are the pros and cons to this?
I would like to ask why they decided to give me a home visit-I haven't had one for many years- but that may not be something a random customer service person can tell me. It is more convenient for me to not have to travel but the centre for assessment is very close to where I live! That's why I'm surprised they are visiting me at home. I am having a lot of trouble with mobility but it's an unseen condition. I feel I know the outcome of the appointment already given what is happening in general... I will do my best regardless.
Any thoughts on this would be appreciated. I know I'm the only person who can make this decision. I'm looking at the forum for experiences of others. I don't have much time. Appointment is on Tuesday. This Tuesday.

Hi buddha,

I will do my best to answer some of your questions -

A claimant does not have to accept an appointment with less than 7 days notice (although this 7 days includes postage if written). This is the same wherever the appointment will be held.

In arranging a home visit, someone has assessed that you have a significant level of impairment. You can change this to an assessment centre if you wish but you should think about whether this might be contrary to some of the things you have said on your PIP2.

We certainly suggest having someone with you, wherever the assessment is carried out.

You are entitled to record the assessment but you must gain permission from the assessment provider in advance if you wish to record openly. You cannot just tell the assessor on the day that you are going to record.

You must carry out 2 simultaneous recordings, cassette or CD not digital, and give one copy to the assessor before you leave.

It is legal to make a hidden recording. However, I must warn you that if this was found out the most likely result would be the assessor terminating the appointment and your file being returned to DWP.

You are entitled to change the appointment if you wish. However, you can do this only one, so you should make sure you have your companion's availability to hand when you phone to rearrange as you will not be allowed to re-arrange a second time.

Yes, thank you for that.
I'm going to go ahead with it as a neighbour has said she would sit in and make notes if the other person is unavailable. I'd rather do it on my own (it is so intrusive) but then it would be my word v. theirs. Better to have a witness. I'm really not up to it but hey, the 'worst' will be over-at least, until the MR and appeal process kick in!

I'll try to get in touch with the result. Wish me luck.

Good luck!