Just passed a free trial code to a local rider I met who does not have a power meter, but was interested in trying some more structured work, and thought TR could be a nice solution for base phases where you mainly just want to dial in riding longer blocks at Z2 vs. SS vs. threshold (for O/U).
I’ve since learned that TR does not support giving you HR targets. In my opinion, this is a big miss, as many younger folks can’t afford power meters right away. Personally, I found HR to be an incredibly valuable and affordable stepping stone to later getting a power meter. I know TR disagrees - but clearly the market for HR-based training has not gone away as power meters remain a minimum of 6x the price - if you can even find one - so not going to debate that point if they don’t want those potential customers.
But this also got me wondering what I’d do if my power meter died and/or I get a second bike without a PM for a while as so many meters are sold out. Frankly, I’d want to train on my very well understood HR zones rather than an absolutely archaic RPE system.
The only option I can see is that you just have to memorize HR zones as they relate to a RPE target (assuming that is exported as part of a workout structure) or relate it to whatever power targets that get exported if you make up an arbitrary FTP. OK, I could do that after riding for many years… but is that really the only option? Such a solution would be ironic given all the podcast discussion about managing cognitive load - but spend some mental energy relating targets to HR from memory, rather than use the built in field on your head unit 
Is there any other way to configure the Bolt and/or something in TR to allow you to get a HR target on screen with outside workouts if you choose to do so?
If no solution within TR/Bolt - I see that Training Peaks supports this field - but the workout builder is pretty limited on the free platform. Does anyone know if other sites like ERG DB or other solutions open a door to specifying a target HR range for each workout interval, ideally in some way that automatically translates the RPE or power target to HR using a table of reference zones that you setup?