I recently purchased a LHG with new LTE6 modem, which, apart from supporting Channel Aggregation, supports some 700 MHz bands : B12 and B17. Unfortunately, in France only the B28 is allocated for LTE networks of all the operators. So, attention les Français !.
Is there a modem, fro Mikrotik or otherwise, that does support band B28 ? 700 MHz is the preferred frequency band in rural area's, so for the LHG and SXT products, this is highly relevant.

Hello
No..

elc48

I recently purchased a LHG with new LTE6 modem, which, apart from supporting Channel Aggregation, supports some 700 MHz bands : B12 and B17. Unfortunately, in France only the B28 is allocated for LTE networks of all the operators. So, attention les Français !.
Is there a modem, fro Mikrotik or otherwise, that does support band B28 ? 700 MHz is the preferred frequency band in rural area's, so for the LHG and SXT products, this is highly relevant.

Currently, NO Band 28.
B12 in R11e-LTE-US
B12+B17 in R11e-LTE6
but you can use popular webpage to found a modem on miniPCIe factor with all B12/17/28 at: https://techship.com/products/category/lte-cat-6/ and you found Telit LM940 LTE CAT-11, GPS, mPCIe.
In my opinion better way is use a common soho MikroTik with USB 1A and USB Modem who have those band's and external antenna if needed.

On google I found that band for France: LTE 700 (28), LTE 800 (20), LTE 1800 (3), LTE 2100 (1), LTE 2600 (7) and I bold the fast one. And those are common in EMEA. Other bands are only to cover more distance with slow speed.

Additional.
Remember that in RF world not exist any universal antenna on all freq.
Look at graph's of Gain for LGHR and SXTR - I mark the 700Mhz for you.

LGHR: SXTR: As you can see, the gain is on MINUS and for you is not good. On B3/1/7 the sxtr and lhgr have got good Gain but the 700Mhz is missing.
In your situation the RBM11G with proper MiniPCIexpress card and external antenna or just simple soho MikroTik with USB 1A and modem who can have external antenna.

Remember that place where only 700/800/900Mhz can work without 1800/2100/2600 better is dedicated MIMO external antena only for 700Mhz LTE. This will be the best.

The gain for 700MHz on the SXT an LHG devices are fine with a negative gain (measured relative to an isotropic radiator) - iPhone 11 is around -4.5 dBi and can still get excellent reception/speeds.

On google I found that band for France: LTE 700 (28), LTE 800 (20), LTE 1800 (3), LTE 2100 (1), LTE 2600 (7) and I bold the fast one. And those are common in EMEA. Other bands are only to cover more distance with slow speed.

Thanks. As to speed: where I live, the radio link is seldom the bottleneck: speed is determined mostly by the back haul network. My Samsung S7, using 700 MHz, usually is faster than higher frequencies.