Uv mapping of buildings: texel density and Substance 3P Painter problem

Hello everyone, I have a method problem and would like to ask advice from those of you who have already been through this.

I do historical reconstructions, mainly buildings and city areas, in Blender, which I usually visualise via Lumion or Twinmotion.

I want to insert a step through Painter to manage materials and add details (like dirt on the edges or in the lower parts of houses).

In Blender, I usually set the Texel density to 1024 px/m but I do NOT use UDIM, so unwrapping produces HUGE UV islands!

Hence the problem:

1) If I import the model into Painter like this, the baking (especially AO) comes out rubbish and becomes unusable

2) If I reduce the Texel density I have to get to about 64 px/m to make all the UV islands fit inside the edges of the UV map and I lose all the details in Painter

3) If I start unpacking in UDIM it will take me ages.....

Can anyone point me in the right direction?

Thank you all in advance