(mod edit: post split from article to keep discussion separate. If needed/useful, can be merged again later)
My take on things:
1- what is the question ?
2- what is the question ?
3- Tagged ports are indeed filtering based on VLAN ids.
4- Your base problem here might be that you are not aware a bridge has multiple personalities as explained in this thread.
IMHO: heavy stuff, may take several readings before you really get it and I will admit I still don’t get it completely myself.
RouterOS bridge mysteries explained
So here again, all frames tagged with 99 are allowed for br1, sfp1 and sfp2.
5- Default settings are not visible in export. If you set it explicitly, it will show.
And it is always better for future review that you are aware something is in effect.