Yeah, pretty much seems to me that this is one of those real ‘personal’ decisions that you just can’t ask others the, ‘what if you were in my shoes’ question.
The pros and cons have been put forward by the earlier posters, so it is now down to you to put them into your personal circumstances ‘equation’
IMHO I would do the next stage asap.
If someone has offered the loan, I would assume it means that they are comfortable giving you the money and the fact that you will repay it. As others have said, take it now while on offer and you avoid the ‘what if’s’ of the future.
On a purely financial level, do also consider that prices of everything really only tend to go up (OK, let’s not get so deep and talk about relative values due to inflation etc.) and you never know, the test may change format in the future, perhaps requiring you to do more.
At least you know what you are in for at the moment.
And, as others have said, just because you have passed Class 1, doesn’t mean you HAVE to take a job there first.
It’s funny, but I was in the same position to you in a way, and so I asked my two cousins (with whom I am going to work when qualified) who run a medium-sized haulage firm that they took over from their father.
Their answer was to do both back-to-back.
Reason being - while you are in exam mode, get all the exam-type things you need to do, done.
Overall, I think coming up with the correct answer requires a good element of honesty with yourself when asking the relevant questions.
There is pretty much always going to be a pro-argument, as well as a counter one.
So, for example, the idea that working Class 2 gains you experience and gets you used to driving a LGV is countered by the notion that you may be the type of person that ‘relaxes’ when working and so picks up bad habits that need to be ironed out at test time.
So, if you know you can be honest with yourself, then you are in a solid position to make the correct decision.
If you know that is not so much the case, or even if you don’t, but others around you are always telling you different - then do take their input on this as you really do want to make the best choice you can.
Interesting question whatever you decide
GL,
Jon