I think you'll find you do better sticking to multi-purpose compost. Seed compost is designed to start seeds growing not to support actually plants.

Good seed compost is a bit like John Innes No.2 (loam and sand) but much lower in nutrients. You could use it but you would have to add extra base fertilser for more mature plants to thrive.

I would also have thought seed compost was rather more expensive than multi-purpose but, as we make our own potting compost I don't really know!

Can we have the recipe for your home made seed
compost please ? Others may like to use it.