Had completly different experiences. As long as the issuing carrier allows KLM agents to touch that ticket they generally will work with you.
During IRROPS [MENTION=9593]AMS[/MENTION] and after checking expertflyer for valid alternatives the agents from the ticketing desk put me on KE & MU metal, no questions asked & very efficient.

DL and KL have a joint venture, so all revenue and expenses are shared. OK is outside the JV. FWIW, YMMV, ETC.

FYI, I have called a couple of times over the years and asked in advance about rebooking when I was worried about a connection, even though it was the routing I decided to book and there had not been a schedule change. Both times I was able to get a supervisor to make a free change to create a longer connection. I did this because I felt that the MCTs were unreasonable and, for whatever reason, the longer connections would just not show up in an online search at all. I called and explained this honestly to the agent and they just made the change after speaking with a supervisor.

This is not something I would abuse, but I do think there are times when it does not hurt to ask. FWIW, I think you will have better luck with them changing the DL metal to an earlier departure than changing the KLM flight.

It's up to the agent but looks like DL is pretty accommodating for involuntary reroutes.

As an example, NYC weather waiver in effect today. This was issued on two days ago (Saturday). I had an Flying Blue award for EWR-ATL-DUS in J.

DL phone lines had more than 60 min wait. I called AF (which is handled by DL) and someone picked up on 10 minutes. She confirmed weather waiver in effect for my itinerary and rebooked me JFK-AMS-DUS with DL over the pond as the KLM JFK-AMS evening flight was fully booked in J.

12 hours after being rebooked, I saw J seats on KLM flight. Called AF/DL back. Agent moved me over to KL transatlantic flight without any hassle. My preference is for flying in J on KL 789 equipment over DL 333.

Ok, we are enroute. Looks like maybe an hour possibly 50 minute connection depending on all the variable factors. Arriving in E, departing B28. Trying to find airport diagrams, really have yet to find it, but is B28 a remote stand or something similar?

Flight is scheduled to arrive early.

Terminal map for Schiphol. B28 is probably a bus gate.

B28 is not remote. On Pier B.

Well looks like we have an extra 20 minutes or so if everything goes as scheduled. Considering we left Atl 20 minutes late we are doing great. I'm thinking B 28 must be a bus gate also. It's a Kim cityhopper.

There is an AMS airport map in the Sky magazine in your seat pocket.

Yes a chunk of Cotyhopper flights are bus gates. Just had one about 4 months ago for ZAG-AMS.

Did this exact routing in Sept last year. Made the connection after cutting through the customs line ahead of scores of people. My bags, however, didn't arrive until about 18 hours later.

Anything above B20 is a dual gate. It can be remote or it can be right next to the terminal. YMMV.

Flight arrived a few minutes early so it's pretty safe to presume that the OP made the connection although 46 from JFK was 30 min early at 5:29 and 124 from BOS also early at 5:25. Both of these were at E gates and 70 at an F gate. I'm not sure if they merge for passport control.

OP, have a great time in Prague. Be sure to have dinner at The Little Blue Duck (U Modré Kachničky, Nebovidská, Prague 1, Czechia) Tram stop 2 blocks away.

Do you mean the gates where the aircraft is parked right there, but there's no jetway, so you walk out into a jetway like thing, walk down the stairs, go outside and walk over the tarmac for maybe 50 meters and then walk up the stairs into the aircraft? It's not much better than a bus gate.