People with multi monitor setups with different DPI, how is your experience?

I'm thinking of getting a 43" 4k monitor. The real estate is going to be AMAZING.

The only thing I'm worried about is the DPI. I use a 2017 MBPr w/ a Dell P2415Q, both of which are ~180+ PPI

I used to have a 24" 1080p and side by side, it became unbearably blurry. For those that have the same rough setup, do you think I would find the LG monitor blurry? or do you find putting it further back helps?

On the other hand, anyone here who have experience 32 inch 4k with 24 inch 4k? That would put the PPI at ~150PPI - ~180 PPI.

I'd love to get the 43", but I'm not sure if I'll find it 'blurry'. No retailer in my area has it, and I have to ship it internationally so I really want to know if it's going to be feasible before I jump the gun.