How do I make a true mobile access point

[bugith]

Hi
Is it the great saver soft I dream of?
I installed it hoping it would help me to have a set it and forget it hotspot with its own static IP, own interface, own manually selectable private IPv4 LAN/size and own dhcp server for this lan... and non-changing SSID+key.
My goal is to run a smb server bound to the hotspot IP for a single silly smb client that can't do name resolution.
This would be just fine enough:
LANip/30 static address, static interface name, static AP SSID, persistent MAC
LANip+1 dhcp server
LANip+2 available for client
LANip+3 broadcast

How can I do this in Android 15? I nearly reached the goal with additional system hotspot settings feature but no IP settings are available and LANip changes on each phone reboot. Static IP feature doesn't seem to apply to wireless interface ???
Well... you guess my goal is not VPN.

Thank you