Hi,
I've kept boesemanis in my 55 before. They were okay but I really think they need more swimming space for their activity level. Make sure to have hiding spaces as my male would endlessly chase the females. They were also food hogs so sometimes other fish were afraid to eat, but I don't think competition will be an issue with tetras and platys.
As for the pleco, they're going to make more of a mess with their waste than they will clean algae. They need to have a supplemented diet and likely won't have enough to eat on your tank algae alone. If you like them that's fine, but for bottom dwellers I think it's best to do either a pleco or cories or loaches and not a combo, IMHO.
Otos are good algae eaters but kind of the opposite problem. If you don't have enough algae sometimes it's hard to get them to eat prepared foods. They are much smaller and also best kept in groups. I think it's a common misconception that a tank needs an algae eater. If you keep up on cleaning and maintenance and regulate lighting you'll be fine.
As for the cories, I would say instead of four and four to go with eight of one kind. The bigger the group of the same species, the more secure they feel and the more their personality shines.
Let us know what you decide! Good luck!