Advice on caulk cracks through primer

[JamieB3009]

Hello,

I am after some advice please.

I have just refurbished some door linings and skirting boards etc. And there is a small crack formed in one particular area. The woodwork is currently primed awaiting topcoat so I would like to address this before topcoat is applied. The woodwork was previously stained orange wood so the steps I have taken are;

*heavy sand down of all the paintwork initially.
*initial fill and repair of damage using two part filler and repaircare as necessary.
*sand repairs smooth and give two coats of zinsser bin.
*final caulk and any remaining filling.
*two coars of benjamin moore fresh start primer, sanding between coats.

Everywhere else the finish is pretty much perfect but just a small crack here. Any advice before I top coat?

Thanks