Would this promote algae or would it deter algae?
In my experience and in theory, yes. Once the plants are starved for something, anything except for light, the algae will take over and use what IS there.
What do you do if you just dont want to mess with fertalizers and doing 50%+ water changes weekly?
The aforementioned person DOES have fertilizers, so if they don't want to "mess with" them, they just won't be dosign them? And even if they do, a 50% pwc every week is not necessary, unless "they" are dumping stuff in.
I would suggest that this person whom none of us know use the fertlizers they have, and start small. With a close watch, they will start to see different deficiencies arise and different types of algae come in to play. Once this happens, they can
1) start dosing the appropriate ferts (according to deficiencies/algae)
2) get lower lighting to slow down ALL growth
3) get TONS of algae eaters and hope
4) watch the algea proliferate