Baby gates for weirdly shaped stairs?

Have you tried safetots? They have standard gates but also fireplace gates and such with add on sections that might be of use?

We used a retractable one at the top of our stairs. It’s meant to be for dogs but works great x

Ours aren't weird shaped but we're planning to get this style gate and depending on shape I feel the style could be more flexible... BabyDan Guard Me Auto Retractable Stair Gate, 55-89 cm width, One-Hand Operation Safety Gate, Metal Child and Pet Gate, White, Made in Denmark https://amzn.eu/d/9IGuzga

We used a cuggl safety gate with small extender (both from Argos) and then had to use a block of wood inbetween the wall and the gate at the top. It was because the gap was too big for regular baby gates and the skirting board was so deep it was leaving a big gap at the top but it’s worked well! Depends on what your issues are though I guess x

We’ve got a retractable one that we can wrap around our curved bottom stair ☺️