Mod-Bit Roof Maintenance Estimates - Help out a new homeowner!

Hi all - I was hoping to get your collective guidance on my roofing situation, as I’m totally clueless and need some impartial advice.

Wife and I recently moved into a rowhouse with a black modified bitumen flat roof that was installed 5 years ago. We have not had any leaks with our roof, but decided to have some roofers come out to get estimates to fix the flashing in two spots (flagged in inspection) and because we noticed some sand/granules in a channel drain that flowed off the roof.

This wasn’t even on our radar, but all of the roofers suggested getting an aluminum coating on the roof, and said that it’s best practices to get that coating every 4-5 years on the type of roof we have. Two of the roofers went out on our roof and inspected it and said that some of the flashing wasn’t done properly, including for the vents and chimney, and that the wall coping wasn’t done properly (nails on top instead of on the sides, etc). All of them said that our roof is in fine shape right now, but that fixing the issues identified and applying the sealant will extend the life of the roof and will ensure that the bad flashing workmanship doesn’t cause leaks in the future.

Thus far, we’ve gotten three estimates ranging from $1900 for only a non-fibered coating, to $4500 to fix the flashing/wall coping on the roof and apply two coats of a fibered sealant.

I go into more detail on the estimates below for your review, but the main reason I want some advice here is because my wife and I think it seems ridiculous to pay $4500 to apply this coating and fix flashing/wall coping when we have not had any leaks!!! I understand that this is preventative maintenance, but it would be good to hear from experts in the field that we aren’t being taken advantage of here. Thanks in advance for your help, and let me know if pictures would be helpful.

ESTIMATE 1: $4500 - reflashing of vents, collars, pipes. $250 each, and we have 7, so $1750 total. 5 year labor and material warranty - chimney reflasing - new metal apron. $450. 5 year labor and material warranty - attic hatch reflashing $250. 5 year labor and material warranty - new wall coping on perimeter made of galvanized 26 gauge sheets, custom made, Z type mechanism to create a triple seal so water will not penetrate into brick wall. $900. 12 year warranty - two coats of fibered aluminum coating. $1400. 4 year warranty on labor and materials.

ESTIMATE 2: $4450. 1 year warranty on everything - reflash vent pipes, base of chimney - new modified bitumen Roofing on front write - Attic hatch reflashing - coat with premium grade asphalt aluminum roof coating

ESTIMATE 3: $1900 - coat roof with non-fibered sealant - 2 year warranty

They openly said they were installing 2 coats . Thats important.

Es 2 only 1 coat.