If you’re happy to spend-then get some proper road pedals and shoes.
You’ll need a stiff mtb to use on a roadbike to avoid hotspot/painful feet and these shoes will be a pain in the butt off road.
Cheap and affective for some.
I bought dedicated road shoes and pedals-comfort and excellent transfer of power.
Just practise clipping in and out in the lounge and stop nice and early/plan your stops until it becomes 2nd nature.
I’m using flats on my touring roadbike (1-23 miles) mainly winter.
My main roadbike I use Ultegra spds but the shimano range varies with weight and works similar. I ride 20-100 miles min on this.
My mtb I use flats in muddy conditions and mtb spds in dry conditions.
Also I can walk on my road shoes abit and my mtb shoes are grippy on rocks.
Think about falling and you will. I tend to unclip a foot through slow movements on my roadbike. Once clear in a few seconds just clip and spin.
If you’re fit-straight to road pedals, if you’re not get some miles with flats until you’re mentally alert for 20 miles then clip in.