Partitioing : is it ok to put my OS at the end of my disk?

I've build a small HTPC; and I have a 2TB HDD in it. The idea is to store only medias on that drive, and to have a separate M.2 SSD drive for the OS.

BUT those SSD still are expensive, and i'll wait some time before buying one. Consequently, I have to put my OS on my HDD momentarily.

Normally, I would partitionate my HDD like this : "boot" (efi) / "OS" / "datas" (which will be almost the entire drive). But knowing that one day or another, i'll use a SSD card for the OS, I will have to repartitionate my HDD so there is only the "datas" partition on it.

Knowing that it's a pain to move partitions (takes a lot of time), I had that idea to use that partition scheme : "datas" / "boot" / "OS". So once I'll have the SSD, I'll just have to remove the "boot" and "OS" partitions, extend the "datas" one, and it'll be faster to manage.

My question is : is there a problem with that structure, and does it change something in terms of speed or reliability to put the system partitions at the end of the drive ?

Thanks a lot !