Gaurs Group payment plan: NRI's tough choice

Been looking for 8 months now and it's getting exhausting. I'm based in Dubai and can't visit Greater Noida often. Booked a 2BHK with Gaurs Group in Noida Extension, construction-linked plan tha. Now they're asking for the next installment, but construction progress bilkul slow hai. Lagta hai they're just pushing for payments without actual work. My agent says it's normal, but I'm worried about delays and hidden charges. Agar main payment hold karun toh penalty lagegi. Anyone else faced this with Gaurs or other builders like ATS? How do you manage these payment traps from abroad, especially with power of attorney?